Hi comienzaBTC,
your Link to CryptoBadger is a good start to build your mining rig...
When you search a good Case for only two GPUs look at "Coolermaster HAF XB (High Air Flow)" or more GPUs take "Aerocool Strike-X Air Benchtable"

I'm mining with 2x Sapphire R9 280X REV2.0 at each 700kh/s and cgminer 3.7.2 - Undervolting to 10.2V and GPU Clock 1020MHz
greets