There are a number of threads on the electric fan business...
If you want a install and forget solution, you will stay with the mechanical fan clutch setup. The only reason in my view to run an electric fan is if...you are constrained by space. You will notice that there is not a lot of space between my engine and teh radiator core.
surf through the threads, search electric fans...etc. See who runs them, how they drive their truck, does it even go offload and does the a/c work. What type of alternator you will need, what other electrical loads will be an issue.
You will also note in your search where a number of people (like I have)...tried the electrical fans...and went back old-school to the fan clutch setup, using GM components that match the engine.
I don't think it would be hard to adapt the cooling components off the vortec series engine to an older model 5.7 (well it might not be...you have to pay attention to the rotation of the components...etc....v-belt vs. single belt). As noted in the picture the vortec uses the single belt drive. If you run an older 5.7 there are various options using the v belt setup. A HD fan clutch and 7 blade fan is pretty impressive on the older stuff, I believe flex-a-lite has or use to have on their web site various 7 blade fan clutch type fans you can simply buy direct from them, to mate with your OEM fan clutch. I like GM fan clutches over the aftermarket stuff if you are running a GM engine.
Any of the electrical radiator fans that work well for cooling will pull a significant load (amps)... Commons swaps are the Lincoln and contour dual fan setup. I like electric fans and think a good matched fan/radiator/alternator setup is hard to beat, but the mechanical fan OEM combination cannot be beat for HD offroad use and the versatility and the forget and run install. There are a few threads where this has been discussed in much detail.
Right now...I start my truck and give it hell (within reason) I run the a/c and go, I'm not stuck watching the temp gauge.