@Angie : Be nice, might not be what you want, but it is what some of us do.

I've done 2 and assisted at least 3 other on the forum here do the same.
OP should start with the SuperCab short bed as it is much easier to extend the rear frame. There will we a strategic cut of the SuperCab frame, a matching one for the Long box frame, welding/fishplating the sections back together and OP has unique truck -
@FatboyShadetree78 at least has the long box/rear frame as pieces of puzzle. The fuel system for a SuperCab doesn't get moved as you are adding after it. If you use Chev 1/2 ton springs, they are the 6" longer from front shackle to axle which is same amount that the long box moves the axle back, so you don't have to more shackles. So, you're down to just adding 6" to the brake line and 12" wiring section for the tail lights.
@FatboyShadetree78 : To use an Explorer 4R70W in a 2wd, you would need to remove everything from inside the transmission, replace the rear output shaft with a 2wd one and put everything back in (you wanted to rebuild the transmission anyways, right?). Then you can replace the output housing with one from 2wd. I have to admit I am cheap/lazy. A Mustang with 3.8/Auto has the exact transmission you are looking for (you get the output shaft and housing you would need anyways). Then you can decide to rebuild before installing or not; I sold the 4R70W 4wd transmission to someone with blown auto in his f-150 for much more than my cost of the Mustang and rebuild. I didn't change anything with my column shifter.
I grabbed the driveshaft from the Mustang while I was there anyway, I think I had to swap it over the transmission yoke to the Ranger driveshaft - 32 vs 25 spline thing. If I remember correctly, if you have a 2 piece drive shaft and use the front part of the SuperCab with the one from your long box they combined to the correct length. Again, I think I had to swap the Explorer yoke to the Ranger driveshaft to connect the Explorer axle. (I told myself I wanted to replace the u-joints anyways).
Something is bugging me that you are losing your speedometer drive (I normally work with just '98-00 Rangers). But that is covered in links provided.
If you are lowering your truck, the Explorer axle is excellent starting point - gears are a little low, but I care more about acceleration than fuel economy. The engine is over the frame crossmember for the TIB arms. so you don't run into anything unless you are trying to really lay frame.