First and foremost, I believe that Windows on Washington serves your area. He is one of the most well-respected, knowledgeable, and prolific contributors to this board and is highly recommended.
On vinyl products, windows and sliding doors go hand in hand. Generally speaking, vinyl is not a great choice for a hinged door unit, so a fiberglass unit from an entry door manufacturer like ProVia or Thermatru is what I recommend. On the sliding door, a window or door assembly will always be less efficient than the typical wall assembly, however the cost difference in labor to down-size from an 8' to a 6' door would more than negate any minimal gain. The Okna/HiMark Elegante has the best performance ratings of any sliding door that I have seen, however the new model from Softlite and the Sunrise unit are also excellent and are in the same "tier" of quality and performance. Those three manufacturers are a few of the top vinyl windows as well.

thank you! I didn't know if he was Washington State or Washington dc so that's awesome that he's Washington DC.
thank you also for the advice on fiberglass for French doors.

Do you think that we can get a satisfactory vinyl replacement with good insulation for the 8 foot wide slider that is not too heavy? The current one has always been a bear even before warping. I'd like to retain a 3 foot opening for moving things out onto the deck. Otherwise I'd consider a 5 foot slider with sidelites to fit that space. I'm ok with replacing with the same size door if my problems are mostly due to a 30 year old door. That entry gets used a lot in the summer.

What are the names of the new model from Sofflite and the Sunrise unite that you are recommending? Similarly, are there names to the types ProVia or Thermatru fiberglass doors that you recommend?

p.s. heading out of town for a few days so my or may not have internet access, just in case I seem MIA.

Sunrise only has one model, and the new Softlite door is the KingsRoyal. All three of them (along with the Okna) would provide smooth operation and tremendous efficiency in any size. I'm not a fan of 5' sliders unless it is absolutely necessary. The opening size sounds okay in theory, but is awkward to get through for larger individuals or if you are carrying something.
In Provia the Signet and the Thermatru Classic Craft are each manufacturer's top line, but they both also have decent "mid-range" choices if budget is a concern. The ProVia is a better product while the Thermatru typically runs a little bit cheaper. There are other door manufacturers that are very good as well, those are just a couple that I have had good luck with.

There is only one "Sunrise" model offered... I will not "technically" dispute your comment Eco, however some elaboration would most certainly alleviate confusion and be greatly appreciated.

I'm a Sunrise Dealer. I know my product lines. Sunrise has 2 patio doors. The standard Sunrise and the Essentials Patio Door. I have no idea what you mean by "technically".

I was just asking you to elaborate for the benefit of the OP. To clarify, there is a Sunrise door that is offered with all of the lines including the "Sunrise" base line. Sunrise only offers one door on their website, so simply saying that they offer two doors without explanation could be confusing.
The Essentials of products is a separate line, and is the lowest line offered.
Not trying to be argumentative, just clarifying for the OP and others that may view the thread.

I don't know how I could be any clearer. Sunrise offers 2 patio doors, not 1. The Essentials patio door is a fantastic buy at a great price point. We sell it for about 25% less than the standard Sunrise patio door. If the Op wants further information, he need only contact an authorized Sunrise Dealer.

Sunrise will be running a special for November for free mini-blinds on the standard patio door. This is normally an additional cost of $720. Makes the Sunrise Door THE door to buy.

Scrappy, just to clarify further as this post is getting somewhat muddled: There is (1) "Sunrise" door, and the manufacturer (Sunrise) also offers a lower cost line called Essentials. The product that I recommend is the "Sunrise", not the Essentials. While I do consider the Sunrise door to be a very good product, it would be third on my list of those three that I mentioned earlier. It has a mechanically fastened (knock-down) frame as opposed to the welded frame on both the Okna and Softlite lines. In addition, it is below the other two in both thermal and structural performance ratings (U-value, air infiltration, etc). That said, it's ratings and quality are still in the upper echelon, hence my recommendation. Ultimately, factors such as installation quality and price should be given proper weight as well... Hope that helps :)

just back- didn't have internet access while away.

EcostarRemodel and HomeSealed- Thanks for all the information and clarification, great to have solid recommendations on those brands and the details on construction. Having "Sunrise" as both a model name and the maker name is certainly confusing so that info clears the confusion. I am still working with the architect but once the plans are finalized I plan to contact WOW for quotes.

There is also a company called Window Nation that is in the Baltimore area that has excellent Angies List reviews, has anyone had experience with or heard of that company?

Be careful with Angies list as I understand it is not as objective as it appears and companies can actual pay to be on the site which would defeat the purpose. But from looking at their site for about 30 seconds I can tell you right now they are not reputable company as the first sentence I read is an out and out lie so........

As I have understood, Angie's List only allows companies to pay to advertise. That doesn't affect their ratings.

Sunrise only advertises 1 patio door. The essentials is just in the background as a drop down.
I belive you are correct HomeSeal.
#1 to windows in washington.