It all depends on your CPU and if it's overclocked.
Contrary to what Corsair say, the H50 can't really handle the heat produced by an overclocked i7 but it should be OK at stock. It's perfectly fine for anything on the 775 socket however.
You need to consider though that in order to get best performance out of the H50 you have to use its 120mm fan as an INTAKE, i.e. sucking air into the case, so see how that will affect your airflow.
If however you do want to go with an air tower cooler it depends again on your CPU - Tecmo34 lists two great air coolers, but if you're at the hottest end of the spectrum i.e. heavy OC on an i7, then consider a Thermalright TRUE and make sure it's Revision C (it has a boomerange-shaped hole cut through the body underneath) or a Prolimatech Megahalem and strap some high pressure fans to it (120mm fan with 9 blades, not 7).
Thanks for all the info! just so you know my cpu is is a core 2 quad Q8200 @2.33ghz on an ASUS pq5 pro MB
Id like to overclock it to 3.0ghz at least, and the way the NZXT Tempest case is set up i can mount the radiator on the top of a case (which has 2 exhaust fans). im not looking to do an extreme overclocking, just middle of the road. At the same time silence is gunna be the most desired feature.
dose this change your opinion any?