I have three 120mm case fans lying around so that shouldn't be a problem. Do you know which is the biggest case in this price range?
The Antec 1100 is actually the largest case. There's tons of room behind the motherboard tray to store cables. Also, some sites consider it to be a full tower case. However, I just consider it a super mid-tower (bit bigger than a regular mid tower; but not as big as a true full tower).