My first advice would be to find out how much insulation you currently have in the attic and what condition it is in. You should have at least R-30 of insulation. If you are adding more than it doesn't cost much more to increase it to R-40. I like fiberglass batts, but blown in insulation is fine as long as it is done properly. This is something you can do yourself or hire an insulation company.

I am sure you were told that as part of the NJ Clean Energy Program you must seal your attic in order to qualify for any rebate. I have never seen any measured results of energy savings before and after sealing. The attic hatch should be sealed since in my opinion it is the biggest source of leakage. This is something you can do yourself. Several years ago I built my own insulated hatch for about $15. If you seen dirty insulation that is dirty in spots, then that is a source of a significant air leak. You can use silicone caulk to seal them, or you can have the insulation company seal and then insulate.

I see that you have gotten some quotes. I also detect that some and possibly all have not done a load calculation for your house. Any HVAC contractor who quotes either a 2 or 3 ton AC for an 1100 sq. foot house in Middlesex County (I am in the same county) NJ obviously has not done a load calculation. If you are going to upgrade the attic insulation then do that first, and then get a contractor to do a real load calculation. If your windows are double paned and fairly tight, then I would think a 40K BTU furnace and a 2 ton furnace are the correct sizes.

As far as equipment goes, I own Carrier Infinity equipment and so far I like it. The Bryant equipment is exactly the same. I am a fan of 2 stage furnaces and AC and in my opinion are worth the extra money. Trane/American Standard is also very good. I have no direct experience with Lennox, but from what I understand Lennox uses unique parts. The parts have to come from Lennox and are sometimes harder to get.

I think you said your current furnace is 11 years old and 80% efficiency. Normally I would say to keep the furnace another 5-10 years. But if you plan to live in this house 10 or more years then you may want to consider replacing and keeping the correct matching AC.

Here are my opinions on the quotes:

Company #1

Quote #1: Carrier Performance AC is good, I don't think you need 2.5 tons and the price seems expensive.

Quote #2 Carrier Infinity 58CVA furnace is very good, but it is only 80% AFUE. I recommend spending a little more money and installing a 95%+ AFUE furnace. The Infinity 24VNA9 is overkill for our climate. You can save money buy dropping down a model or two and getting an AC that has a SEER rating of about 16. If the AC is sized properly and is 2-staged then I highly doubt you need a whole house dehumidifier. That would be a waste of money in my opinion.

Company #2 and #3

I am not an expert on Lennox, but I think some of these models don't compare that the Carrier Infinity in terms of features. The fact you are being quoted different AC sizes is a red flag for me.

Company #4

Quote #1 Bryant Legacy 2.5 ton for $4600 seems reasonable. I would want to see a load calculation to see if you really need 2.5 tons. If you keep your current furnace you will have a mismatched system. It will work, but you don't know the SEER rating,

Quote #2 Bryant Evolution is the same as Carrier Infinity. Very nice equipment but the price seems high. Here is quoting a 2 ton. So why is he quoting 2.5 ton in Quote #1? I see no size listed for the furnace.

Quote #3 He now quotes the 3 ton size. I guess he thinks you may want to hang meat in your basement. A 3 ton AC, even if it were 2-stage, is going to short cycle and you will still have a humidity problem. Once you discover this he may suggest getting a whole house dehumidifier. Correct sizing is critical. This guy does not seem to care.

In summary you haven't found a good contractor yet. Carrier rebates start March 1st. The March - April time frame is the best time to get quotes in our area. Contractors are not busy and the pricing is a little better.

Mike, I think the reason they all priced me for 2.5Ton AC is that I told them that I would be using heating and cooling for both main floor and basement and I was concern about the humidity.

Actually Bryant quotes#2&3 for furnace is 60K BTU.

Do you think the quote for Carrier 80% furnace and 19 SEER AC is high? How much should I be expecting if I were to go with carrier infinity 95+% efficiency furnace and 16SEER AC?

If you have a typical basement where most of it is underground, then the basement represents a small heating load, and no cooling load. An over sized AC will short cycle and do a poor job of humidity control. You would be better off slightly under sized than over sizing the condenser. If your basement is dry then I think you should be able to bring down the humidity below 50% with a properly sized AC.

The Carrier quote seems high, but the 19 SEER AC may be the reason. You pay a lot of money when the SEER starts going above 16. We live in a cold climate so it makes more sense to get a high efficiency furnace and a lower efficiency AC. You may end up close to the same price, but in terms of operating costs you should be better off. Get some more Carrier quotes. The 95% AFUE furnace should qualify you for a state rebate.

When I was shopping in 2009, I decided to go with Carrier and got quotes from 4 Carrier dealers. There are several in the surrounding area. The one I used does a load calculation before presenting a quote. He then presents several variations of equipment to fit your budget.

You may not need zoning to accommodate your basement heating needs - correct ducting should take care of that. A smaller (preferably 2 stage) AC will provide dehumidification with the option to add a whole house dehumidifier at a later date, if necessary.

Hi Mike, How much price difference should there be between Bryant Legacy 2.5 ton 113ANA and Carrier Performance series 24ACC6 2.5 ton?

The Bryant Legacy is equivalent the Carrier Comfort series. I am going to estimate in the Bryant will be $500 - $700 less than the Carrier. I am not sure on pricing, maybe someone has more accurate numbers. But the Bryant is a step down and should be less.

Mile, I decided to just add AC to my existing furnace. I called and asked about the NJ energy audit and in my case, since I don't have AC right now, installing new AC will be increasing energy cost and would not be eligible for energy rebate.
The company#1 is going to include media filter cabinet for carrier 2.5ton 24acc6 for $5,361-$200 rebate from carrier so my final cost would be $5,161 so I am thinking it is not so bad?

I am going to repeat what I said in my first post. I don't think you need 2.5 tons. It would be nice to see a load calculation since you never had air conditioning.

The price seems high, but I don't know what electric work needs to be done for a new installation.

There is a NJ Cool Advantage rebate of $300 if the equipment is 16 SEER and 13 EER. It requires the contractor to submit a Manual J calculation. You probably can't qualify with a mismatched system, but it is worth investigating.