If you are going with those monstrous fans you should really get the HWL GTX like millertime already suggested.

Those Bitspower blocks for the 5870 seem to perform very bad compared to competitors so I would stay away from them:

http://www.xtremesystems.org/forums/...&postcount=395

Whole thread:

http://www.xtremesystems.org/forums/...d.php?t=232879