Wow, so that means he has to find a 95 96 or 97 to do this swap. That's definitely limiting.
No, that means that those three years would be the easiest EXPLORER donors for his swap. Any of them can be used and made to work.
Since he's wanting to use a 5.0 and a T5, the easiest do or would be a Foxbody Mustang. That would give him the engine, the transmission, a fuel system that is compatible with what is in his truck, and an EFI system that will require minimal modifications.
His 2000 Explorer engine (like all Explorer 5.0s) is the most compact accessory drive of any factory 5.0 which helps with fitment in the engine bay, but that is the main advantage that it has. To use his 2000 Explorer engine he will have to make his fuel system work with returnless or convert the engine to return style. He will have to have PATS disabled. He will need to get a 50oz flywheel. He will need to modify the harness to work standalone. Several other changes will have to beade, all of which are detailed in various threads and parts of the website.
The easiest way for him to overcome the fuel supply issue would be to upgrade the fuel pump in tank and run a fuel pressure regulator in the fuel line. FPR outlet to Explorer fuel rail, and return going back to the tank return. Other option would be to acquire a return style fuel rail and injectors from an earlier Explorer (maybe any 5.0?) and hope that the ECU doesn't need retuning to work right.
As for the interior. First off are you familiar with the years that we are talking about? There are so many differences that the suggestion seems comical.
Not much beyond the seats will go into the 91 Ranger. The seats might fit with a track change, but that doesn't mean they are better depending on what he has now. The long center console will not fit up to his existing dash well. A short console could be used, but I've never seen a higher optioned explorer with one of those.
The dash is very questionable and would be a huge undertaking if it could be made to work. The Explorer and later Ranger bodies and dashes were very different. It definitely won't bolt in, I'm not even sure if they are the same width and have the same curvature at the firewall. It would take a while lot of work get any of it close to fitting, I don't even want to think about making it look right. Once you got the dash to fit to the body you'd still have to figure out how to make all of the HVAC stuff work together, because those components are even more different.
Any thing can be hacked together and, given enough time and money, can be made to work and look nice. It sounds like OP doesn't want a hack job, doesn't have a lot more to invest, and feels like the project is already taking longer than he would like. I can't speak for everyone else's suggestions, but IMO with mine he could probably pull the engine, part the rest to offset the parts cost and have it done relatively quickly.