Why anyone would use a GPU only block is beyond me (unless maybe that extra 40 bucks is just tooo much).

Why leave all that heat inside the case (where you are trying to evacuate it from, as well as using sinks where, contrary to what some would state, circulation is usually poor (thats why the card manufacturers use FULL COVERAGE fans and sink units).

Use a full coverage block. It's simply far better than a single block with sinks, it means you wont have to blast your case fans and your card will be much happier overall.

The Koolance blocks kick ass btw.