I've got a nice piece of oak on top of mine, plus a tower, plus I just made a collar for it. I definitely am tired of always having to roll the keezer away from the wall to open the lid because of the tower. Plus I can get 8-9 cornies in there, and I don't want to tie up so much cash in tower taps to serve that many.
Check craigslist for CO2 tanks. A while back, I found a guy in Nashville who had like 15 20# tanks, selling them for $5 each. I got two for me and about six for a local brewery to use.