Even I think a 3 x 360 rads is overkill. Maybe a thick 480 + a thick 240 or 120. I think the Koolance kit looks pretty sweet. (get fast fans, I plan to WC my CPU with an XSPC RX240 kit + 4 CM SickleFlows, you might need faster fans though). I'd love to get my hands on a single GTX 580. If you plan to WC, buy from EVGA. Even if you break the card while removing the stock cooler, your warranty is still valid.
Edit: An RX360 with ~2000RPM fans (and 1.5GPM flow rate) will get you a 15.41 C delta. Decent enough for GPUs.