Oh! You will have so much fun with them if you get some!
I ordered from oceanrider.com because of the great 400+ pages of tutorial they want you to read before your purchase. A lot of people say their prices are too high but, I compared their 'specials' prices to that of seahorsesource.com and found that they are the same. Seahorsesource.com also has a great reputation for their horses and a great probiotic that I bought from them to dose the tank daily with. From what I hear, Dan from Seahorsesource.com is great with his customers and he can be found on the seahorse forum always helping with questions and concerns.
There is a forum at seahorse.org (click on discussion forum when on home page) just for seahorse people. The forum is a bit of a pita to get accepted to but, they are a great group of helpful people with seahorses. They won't tell you "don't get seahorses cause your inexperienced and they will die" and "your tank has to be at least nine months old before putting seahorse in or they will die".
I'm setting up a tank for dwarfs soon, too.