I like The Drip Store because they have a good tutorial as well as a forum where you can ask questions of the staff about what would work well and they will basically custom design a system for free including all the parts and costs.

For pots your setup need not be very expensive, but it can be difficult getting pots evenly watered with drip systems as the water tends to run straight down rather than move laterally in the mix the way it would in the ground soil. If you check out the forums at this site you will see some solutions to this problem. Often just using a mini soaker hose in each pot does the trick.

I use DripWorks. Their website is located at http://www.dripworksusa.com/