There's different types of fans. But lets say we categorize them...there
1 - Silent fans
2 - Performance fans
Your case allows 4 fans in 120mm. If you got it new, it should already have 1 fan included. You can simply go and buy 3 more fans like the one provided.
If you just want to go buy 4 new fans then here are my recommendations (though I'm not sure which country you're in...)
Noctua make really good fans (particularly silent fans). You can find them on sites like NewEgg, NCIX, etc.
Hope this helped.