The AC70 is incredibly easy to mod to a fuge.
Here's what I have on my 10 gallon:
70W 14K HQI MH
CPR 3.6 Gallon Aquafuge (26W PC over it)
Seio 620
Running the tank bb, with about 10 - 12 lbs LR in the tank and 8-10 lbs in the fuge.
I love this set up, but I would have gone with the 150W bulb in retrospect. So that's what I suggest, however this isn't too much of a budget tank (about $310 for the 150W and the PCs on ebay, and $100 for the Aquafuge).