I converted mine with good results. The electric fan was the same diameter as the old viscous fan. The problems I encountered were finding a low profile model; most don'e give you enough room to clear the engine block. I ended up with about 2 cm clearance; it was no problem. I got mine through Jeg's aftermarket parts; order their catalog. I THINK the web site is JEGS.com. Also, prefit the fan guard in place BEFORE you zip tie the fan to the radiator. I had to drill a small whole to route the wires which you may not be able to do if you cut the wires too early. I wired mine directly to the battery so the fan would run after the motor was turned off. (I got tired of parking the car for 5 minutes in the summer to start up the car and find the temp redlined. I NEVER had a problem with the battery running down.)
In hind sight, I would rather gone with a two-fan set up, each with their own temp guage. One to come on at 90 degrees C and the other at 100 degrees to "stage" the cooling. But, this would require you to fabricate a thin shield to route the air flow since you probably wouldn't be able to use the old fan shroud.