Doing a carb will be harder and more wiring involved, not to mention more expensive. For carb, you will need an adjustable fuel pressure regulator that will adjust down to 5 psi. You will also either have to buy an intake and carb, or rebuild the motor if you get a carb motor. You will have to rewire the fuel pump relay since the ECU controls it, you will need to get fittings to adapt the efi fuel lines to the afpr, then the tranny, you will need to use a mechanical auto trans or go manual.
With using the explorer setup, all wiring goes through one plug, there will be only 5 wires to hook up (add 1 wire for each water temp and oil pressure sensor if you want to use the stock gauges, 3 more wires if you want the diagnostic port, which I recommend) and a dual sump oil pan/pickup tube. I can even help you out by making the wiring harness modifications for you to make it a true plug n play swap...
SVT