What Royce is suggesting is what your trying to accomplish is more then a simple bolt on install/upgrade. Just installing an electric fan is not going to solve any problems on its own and a good chance it will cause your more issues.
To properly run an electric fan there are several things you need to do to achieve good results. First is going to make sure your coolant system is up to speed. If you have an over heating issue with the stock fan, radiator, engine etc you need to address this first. You should not have an overheating issue in the stock configuration and adding an electric fan in hopes it cures your issue is the wrong approach. If that is all good I would recommend an upgrade to a 24" radiator over the 20". this gives you a little more options on fans too.
An electric fan is a good upgrade for several reasons but its not as simple as hanging one on your radiator and calling it good. First you will need an upgraded alternator, which should also get new cables built to and from the battery/alt. I would suggest proper grounding from battery to frame/frame to engine/engine to firewall.
Your fan choice is important and you need one with a shroud. Ideally the fan is large enough or the shroud as accommodations to allow engine air flow during cruise speeds to avoid creating an overheat condition when moving. Too many fans are too small or have shrouds that restrict air flow to only the area of the fan.
You will need a way to control the fan. The easiest is a set of relays with a temp sensor on the radiator or more preferably on the intake for proper temp readings. The issue here is the fans are typically on or off, when on they will be running at 100% and be quite loud. This also does not allow proper control of coolant temp as you can overcool or cause large swings in temperature. I suggest installing a fan controller that is PWM(pulse width modulated). This will allow your fans to run from 0-100% depending on demand. You can adjust settings to dial in your ideal running temperature. They also give you the function of fan speeds with AC if you have it as well. The fans and controller should all have their own circuits, I suggest an Auxiliary fuse/relay setup that pulls its main power from the battery and nothing on your stock wiring
On the subject of alternators look into a 1-wire. Its internally regulated and simple install. I running a powermaster and its been great. Looks close in style to the original l as well so it doesn’t look out of place. You do not need any of the factory external regulator circuit when using a 1wire alternator.
Ive done all this on my car already and I have pictures posted of what parts Im using and how its installed