If you run twin electric fans (like one of Flex-A-Lite's setups) there's enough room between the fans to clear a long water pump.

I plan on going to twin electrics in the future, but for now I still run a mechanical fan.

If you're looking at accessory drives, I'd highly recommend looking at Jones Racing Products. I am glad I did...I was able to work with them to get exactly the setup I was after, and it works great.