after being in the hobby for a couple years now, i am beginning to view my 29 as a "nano" as i try to fit ever more and more frags in it. buying lights and filtration for something like a 10 gallon is not going to be much cheaper than a 29 gallon, or even a 55 gallon.
i kick myself every day when i wake up in the morning and go to check out the tank.
"why didn't i just shell out the extra 30 bucks for a 55 when i started and built my system around that?"
moral of the story, unless you have a burning desire to get all bonsai with your reef for space or aesthetics, i would definately go bigger, because as you learn more and more, and see more and more stuff you can keep, you are going to find yourself having to get rid of prized specimines just to try something new. save yourself the heartache and go big on the first go! bigger is better!
heck, most people here would probably rate a 55 as a small tank
if you decide to stay with the small tank idea, hit nano-reef.com if you havent found it yet. they will have entire boards with answers to the questions you didn't even know you needed to ask yet. things like filtration, lighting, water testing and parameters, and what livestock goes well in small tanks, and what is better left for the bigger tanks (just dont ask if you can have a tang in a 5 gallon tank, save yourself that flame!).