Thanks for all the replies. Much appreciated

This is the equipment I’m using:
Core i5 750
Sapphire Radeon HD 5850 (just one)
Gigabyte GA-P55M-UD2
G.SKILL Ripjaws 4GB PC315000 1866MHz CL9

I hope to be able to get a stable 24/7 overclock of 4Ghz.

I planned on getting the Heatkiller LT as I thought it was the best performing block out there. Wasn’t aware of the Swiftech XT being better. How does these two compare in terms of water restriction?
Are there any tests out there comparing them?

How does the MCR 420 compare to the XSPC RX480 in terms of performance and restriction? I lean towards the XSPC, but I really like Swiftech’s price tag.

If I buy a MCP350 with a XSPC Res Top, will it be good enough for this loop?
1x quad rad (MCR 420 or XSPC RX480)
1x CPU block (Heatkiller or Swiftech XT)
1x MCW60 (I will buy heatsinks aswell)
1x MCW30 (maybe I’ll exclude this one, but it’s pretty cheap and low restriction)

What if I add another component later on, like for instance a second rad or GPU block, will a MCP350 still be good enough?