The HAF 912 I suggested would be pretty nice for the price point, it has a lot of room. I use a Core Contact Freezer 120mm heatsink/fan combo, and it fits very nicely in there...and it's pretty dang large. Also big enough to fit the higher end video cards (since they can be fairly long and bulky). Not sure about the space in the 300, but it seems smaller overall, and the price point is about the same.
If it's any incentive, you can mount some giant fans in there. I actually bought an extra 120mm and a big 200mm fan to add on to the 2x 120mm fans it comes with...those two can fit in the top, a 120mm in the back, and the 200mm fits nicely in the front. It has some monster airflow, lemme tell ya.
The fans it comes with are nice and quiet though, around 17dB (only pushing 1200rpm). These are the extra fans I got:
Newegg.com - COOLER MASTER Megaflow 200 R4-LUS-07AB-GP 200mm Blue LED Case Fan
Newegg.com - COOLER MASTER R4-L2R-20AC-GP 120mm Blue LED Case Fan
Both peak at 19dB, so it'll be nice and quiet. The loudest fans in your rig will be the heatsink fan (some of those stock ones can be kinda loud) and your PSU fans (not sure what dB they run at). Just some food for thought.