Over heating issues w/e-fans are from using a fan to small/cheap fan-claiming to be a hi-cfm, or t-stat failing(common even w/oem e-fans) or having the t-stat falling out of the radiator. The best way to avoid the issue is buy a quality e-fan like the Black Magic or use the Taurus(though it can draw more amps), and either run dual quality t-stat, or do like I do and leave the fan on all the time. Having the fan come on w/the ignition does cause the warm up time to be delayed by a few minutes, though if I wanted to I can turn the fan off with my ground interrupt(for water x-ings) to speed up the warm up time, but I am usually never in that much of a hurry. I prefer this set-up since I can here it running, and I don't have to worry about the electric t-stat switch burning out/failing.

The main thing when going to an e-fan is buying a quality one, and not trying to solve an over heating issue you already have. An e-fan regardless of its size isn't going to solve existing overheating issues.