i would definetly not get BTX form factor. it has come out for a while now and it still has not caught on because its an Intel only form factor. and then your cpu cooling fan also has to be special and support btx also. the btx concept is good but in reality it sucks. as for a full tower case i would reccomend the cm stacker.
MacBook 2.2GHz Santa Rosa | 120GB HDD | 4GB ram
Intel C2D E6300 @ 3.2GHz | 4GB ram | 880GB total HDD space | Gigabyte P965-DS3 | eVGA 8800GTS 640mb | Corsair HX 520 | Audigy 2 ZS platnium | Antec 900