I initially looked at those (before I got pointed to the ford fusion fan), but unfortunately, the cost is hard to justify.
I was wondering if the AC fan stays or needs to come off (even with the fusion setup). It seems like it's mostly there in case AC kicks in at low engine rpm and the clutch fan is not pulling enough air, but it doesn't seem anyone has removed it in the fusion fan setup.

 

I checked out the controller the person used in the Fusion post and it looks like it's provisioned for AC input. You should be able to splice it into the compressor and have the fans come on when the compressor is engaged. Then you can remove the aux fan.

Also, if you ever plan on fording water, I recommend adding a kill switch to the fans so you can turn them off in the water. Electric fans will short out in the water and you'll be in trouble.

 

Summit Racing sells quite a variety of different models. Up to 6,000 cfm from what I found. A P38 alternator makes sense (if you can get a genuine from the junk yard for cheap) since it has 150A compared to 120A stock. It is bigger but fits. You only have to rotate one half of the housing to the other by 90 degrees, otherwise it's very hard to get to the electric terminals.

 

I planned to have one permanently go on with ignition, and the second one on a temp-controlled relay (using a Flex-A-lite kit). Call me crazy, but I don't have the A/C compressor hooked up (when I got the truck there was no fluid in the ac system). It only gets up to 85F a few times a year so I never bothered to hook it back on - just sweat a bit, lol. That's why I'd like to get rid of the AC fan, just blocks the airflow from my perspective
I did a P38 alt swap pretty much right after I rebuilt the engine (the bearings were shot on the stock) - that was the recommendation on the forum and sounded like a good idea.
The e-fan is pretty much the last "essential" mod on my list.