What are the specs of the computer you plan to build?
Picking out a case that you like is something you have to do on your own...only you know what you like. Just make sure you get a good quality power supply.
This thread has a list of recommended power supply brands. Some case brands include a good quality power supply with them...these brands are Antec, AOpen, Enlight, Enermax (with a Enermax power supply, not the PowerUp) and Thermaltake.
As far as cooling goes, it depends on the specs of your system. Basically, you'll want at least 1 fan on the back of the case removing warm air from the case. You can have 1 fan in the front to bring cool air into the case.

Cricket