what case do you have?
What size are the fans?
Good makes are coolermaster, noctua.
I got 2 coolermaster LED fans in my case and they move alot of air, aand they quiet.
The noctua is the quietest fan, but a little expensive.
But those are 120mm fans. 80mm fans are not worth it IMO, cause they are so small, tehy rev up to move air, and they whizz....