Suggest some case fans...

Noctua from my experience has some of the best quality fans, but you really dont need to shell out huge amounts for good fans. The air cooling in your case depends less on the fans, than it does the configuration and airflow as most fans can push enough air and be fairly quiet with no problem. Good cable management is important, and the rest depends on your case.

Only things you should look for when buying fans is RPM, Size, dB, and the amount of air it can push (CFM). Most fans have the same specs, with some fans being slightly more efficient. You wont be seeing a huge difference in buying $20 fans, or $9 fans, perhaps other than some noise differences, and quality differences. S ythe and Noctua are the high quality ones, Corsair being pretty good, and other brands will work well, but not exceptionally so.