You might also keep an eye on Craigslist. A lot of times you can find someone who has upgraded and can find something less expensive than new, BUT you do need to know how old the bulbs are and if they're included as they can be pretty expensive in and of themselves.
My advice is to not skimp on the lights and get what you need to keep what you want from the get go. Upgrading will cost you far more in the long run. I have a 37 with the same footprint as the 29 and am currently running a Current USA Sunpod 150W metal halide along with a 24" Hagen HO GLO strip outfitted with an actinic blue. If I could rewind the clock, I'd have gotten the 250 metal halide with 2 actinic strips (can't remember what they call this series - Outer Orbit maybe?). It would have cost significantly more, but I would also feel more secure about the lights being sufficient to support anything I wanted AND it would look cleaner.
As Carey said, nems are very light demanding. My issue with them has always been keeping them out of powerhead and filter intakes when they decide to go wandering. Knock on wood, I now have a long tentacle that seems to be happy under my current lights and is staying put.
The bubble tip I had before him decided he wanted to live under the live rock, bleached out and died. I couldn't get to him without dismantling the tank to reposition him in the light. I was hoping that he would come out and get some sun. When he finally did, it was too late.
