What rpm for 30FPI rads?

i saw the new noctua fans, and i though i wanted the industrial ones, i have a 2*120 30FPI rad,

and the new noctua industrial 120mm ones has configurations of 2000rpm and 3000rpm,

which one would be the best "bang for the buck"?

oh, the thickness is acctually only 34.5 mm thick:

XSPC multiport radiator EX240

http://www.xs-pc.com/radiators-ex-series/ex240-multiport-radiator

2000RPM or 3000 RPM?

here's the fans:

http://www.noctua.at/main.php?show=industrialppc

might make alot of noise when installed on a radiator.

 

well if you read the xspc website then you would get the answer :) XSPC themselves suggest low rpm fans. This would mean even below 1200 rpm.