I'm not up on the latest with CPUs so can't comment on the benefits of a 2600K over the i7.
However Metalnwood and I have spoken in PM a bit about the cooling of the 6970, as I also have two of them close together, and the temperatures that they generate, especially the primary, does give me some cause for concern.
Having done quite a bit of web searching on this, I think the only viable alternative at the moment is water cooling.
PowerColor already market one as reviewed here
but as we already own the cards we should be looking at aftermarket solutions of which there are plenty on the web.
Whilst to install this on to one or both of the cards is not going to be easy or cheap, it definitely would be a cheaper solution than going for a new Mobo and CPU.
I have yet to make my mind up which way to go.
I'm somewhat put off by the reality which is, at the moment neither of the two flight sims that I am currently using, this and Il2 CoD, utilise Crossfire and until they do I can't justify the cost. Until they do I should (but probably won't) really remove one of the cards!! :huh: