i have the same cpu and ram and im using the Prolimatech Armageddon heatsink...It's slim and it's made for situations like yours with tall ram...I won't have the problem in installing ram in all 4 slot...the heatsink doesn't come with fans though you have to buy them seperate...It also uses 140mm fans...Check out my video on youtube i have my system on there with the Corsair Vengenace ram in the 1st slot with the heatsink and fans installed...
I just ordered my new build and i had the same question. Im getting an ASUS mobo though. I contacted Arctic about their Arctic Freezer 13 PRO fan and they said the cooler wouldnt block any ram slots. The same goes for the Hyper 212+ cooler.
However for bigger coolers, i dont think theres many at all that block the first 2 slots. SOME block the first one slot, but still allow for slots 2/4 to be used for dual channel memory.
Since theres very little point in anything more than 8GB RAM or even 4GB ram (for gaming), im guessing you'll only be using either 2x2GB or 2x4GB RAM so there shouldnt be any problems
The prolimatech armageddon is going to be hard to find... The archon is a good candidate but is a tad pricy.. for that price I' d rather you get this: http://www.antec.com/Believe_it/product.php?id=Mjc2OA==... which you can find for 60 bucks more or less.. A cooler master hyper 212+ should let you get at least 4.2 ghz. And are you using dual channel ram? because if you aren't going to be using all the slots then you can jsut put your ram into slots 2 and 4, and that let's you get cooleres that only overhang the first ram slot. For future upgrades, I believe corsair said their new "low profile" vengeance is compatible with their vengeance ram so you could use that in 1 and 3 for upgrades.
To sum it up, if you want a less expensive cooler that definitely gets teh job done, go with the Cooler master hyper 212+. Some may say it overhangs the first slot, but I'm not sure if it will on yours.
If you want to go above 4.5 ghz go with the antec kuhler h2o 620