Yes both trucks are 4x4, the 2001 has the push button style, not really a fan of those, I'd rather have the lever and manually do it like the 95 has, my dad's 96 is also 4x4. I saw plenty of 2wd and gas models, but weren't interested. Michigan gets snow and at times 4x4 is really needed. Besides that, it's a truck mainly for wood hauling, and being a diesel, all of the weight is in the front, so it's terrible off road so it really needs the front wheels turning so I don't get stuck on wet grass =). The big mod for the Toyota T100's is manual locking hubs for mpg and less front axle wear, but the 95 came with them stock.
For the propane setup, it would be a proper kit designed for the truck if I tried it. It monitors boost levels and throttle to keep the propane at safe levels. I'll have to read up on the system more, but I think it's pretty interesting. Probably won't be touching anything like that for a while since I'd want to atleast get some miles on the truck to get something for a baseline.
Here's a photo of the truck, not great quality photos, they are from the craigslist page. The push bumper goes down a fair bit, so I guess that gives a bit of an air dam effect. I don't think it has any mud flaps either. The hood latch is rigged up some, I have to bend the hood back down and get a new cable installed. For a michigan truck from 1995, it's in quite good condition body wise. Thinking about painting the custom metal parts black to make them not stand out so much, that or a similar red color to make it blend in more. Not really a big person on looks, but gray and red don't really match too well in my eyes xD.
Talking about trucks, I can't remember which was found to be better on here, a flat topped topper/cap, or a tonneau cover. I'm thinking the topper was slightly better, but for wood hauling, the tonneau cover would probably be more ideal since I can remove it if needed. Catcher is, I have the topper, not the tonneau cover lol.