Honestly it would be much easier to do a manual transfer case. Your truck is an auto correct? If so you don't have to worry about any of the t-case shifter bosses as the autos all had them. You wouldn't have to worry about any wiring harnesses and making the 4wd lights work is cake with the manual case. Your only drawback would be the loss of your console, but I would trade a center console for 4x4 any day, especially when it comes with the reliability of the manual shift transfer case. Although its your truck and your decision on the best approach for something like that. I have no experience making an electric shift case work properly, although it seemed a bit complicated for my liking when Griggs did it.
Also as far as what parts you can use. Keep in mind 95-01 explorers also used the same drivetrain parts as 2001-up rangers. When I did my swap I actually used the wheel bearing units from a 99 explorer. Also explorers never used the PVH setup like rangers did so you wouldnt have to worry about the wheel bearings being the correct ones or not. Instead they randomly used a CAD (center axle disconnect) on the axle itself, which you would avoid for sure. Not all of them had that though.
Also on my swap the only interior parts I needed were the shifters/boots for the manual case setup. And I didn't need any engine parts whatsoever. Although on 04-up trucks I believe you will need the ABS module for a 4x4. On my '03 the ABS funtions normally without changing the module.
2003 Ranger Regular cab 5-Speed 4x4
D30 SAS | KING Coilovers | Deaver f31s | 4.88s | Detroit TrueTrac | Eaton E-Locker | 35" MTZs | 1354m | RE Long Arms | Currie AntiRock