I would go with the 29,but you really can find a 55 if you wait and search ebay,craigslist for the same price.I just got a 55 setup with everything for 56.00 tank,wood stand lights,fluval 304 im picking another one up soon for 80.00 all you have to be is patient.
Be patient CB and you can take the money you have now and get a 55 and you wont have to worry about people flaming you or anything anymore because IF you wait and get a 55 you will have enough room for some of your fish still. Please take this advice that is given to you and get a 55 gallon, not a 29 or 30 octagon, a 55 please.
But he doesn't need another 29 yoshi...if he had a 29 and a 55 he would be SET! No more flames or posts about not flaming you....come on man, you have to see the light!
Re: craigslist etc, everybody keeps yelling "you can find oodles of tanks for dirt cheap on CL!!!!!1!" but that's not always true. I checked CL in his neck of the woods and it was all stuff like 29G for $150, 55G for $400 etc. I agree CL is usually the way to go, but if you're not in a big fishkeeping area you could wait forever for a decent deal on a used tank. Took me almost a year looking to find my 160.