Thank you very much.
I am aware that secondary cooler is expensive and that was one of the reason why wanted to buy one that allready has two of them. But, I saw that if I can find right screws, any cooler that supports lga 1366 can fit- Arctic Cooling Freezer 7 is one example. I dont know about max height of the cooler, but suppose that anything bellow 140 mm is fine since Freezer fits.
About CPUs- I would really like to buy those that you recommend, but thats out of my budget. I will go either two X5650 or X5660 since they have ok price on EU ebay. Anything more expensive and I am allready in dual lga 2011 kind of budget which is something I am tring to avoid.
I want best bang for the buck. 
24gb of ram is ok for my needs (VM, 3d modeling) so I will look for dual E5620 or E5630 setup with that amount of memory. Total cost of the system with dual hex upgrade will probably be in 450-470£ range.