whats the general opinion on the xspc ex360 kit, compared to the rx360 kit. the ex360 has a better cpu block but the rx360 radiator is twice as thick, would the ex360 rad cope with sli 470's and a oc'd bulldozer
GTX 470 has a TDP of 215 watts; running two would be around 430 watts. My thinking is Bulldozer is a 125w TDP part at stock. This brings your total to 555 watts at stock speeds. A RX360 is only good for up to 575-600 watts with 2000 rpm fans having good static pressure (Scythe Ultra Kaze's come to mind). You aren't going to have much head room left to overclock that CPU unless you add another 120 or 140mm rad to the loop (at least).
EX rads are situated as such: RS > EX > RX. The EX kits have the Raystorm block where the RS and RX kits run the Rasa block. Either block is very good. What GPU blocks are you going to run? Have you considered a custom loop? The only downside to the Rasa/Raystorm kits is the pump- it is designed for a CPU only or CPU+ 1 GPU loop. People run more than this, but for the amount of gear in the loop, why not just go custom from the start?
What is your budget? Even with the RX360 kit, you are looking at around $450 for this loop when you add in the GPU blocks and additional fittings.