RPM wise what are you looking for?
Current favorite for (cheep) low noise fans are Yate Loon's.
Zalman, Arctic Cooling and Scythe (non fluid dynamic bearing version) fans are also not bad for there price.
And for higher priced fans.
Scythe (fluid dynamic versions)
The cheep (read free) way of controlling fan speed is the 7v or 5v modhttp://www.techpowerup.com/articles/other/137
But for fan controllers
Zalman ZM-MFC1 is a good simple controller.
It will not let your fans drop below 5v of power, and it allows you to still send the fans RPM signal to the motherboard or any other RPM monitoring device. But if you don't like the looks it should not be very hard to just make a new faceplate from a drive bay cover.
Also could pick up some ($5) Zalman Fan Mate 2's if you only have 1 or 2 fans you need to control.