well ill finally get around to typing this up. Well i built my own controller set up, and am currently running only one 16" fan. The temp controller i bought from auto zone for 20ish bucks. Then i wired it up with a relay and still plan to wire a master on off switch as a saftey back up incase the relay or temp controller fails... I can draw up a wire diagram on the computer, but i dont have time right this minute to do it.
I would imagine the hardest part for the average guy to do would be taking the stock fan clutch off the water pump. I had a special tool that i had access to that hooks up to an air hammer, broke the clutch loose in 5 seconds. But for me the hardest and most time consuming part was laying the wires, creating the harness, and figuring exactly how i wanted to wire the whole thing up.
Now for the pics:
Ground wire
Hot wire I used a fusible link instead of a fuse and you can see that greyish brown wire is the fusible link part
Controller and relay stacked
you can see i twisted the heads of the screws off of the crappy mounting screws it came with.... The screws were bigger then the holes in the supplied bracket, so i didnt take too much to break them off, by hand with a screwdriver.
temp probe and top corner of the fan