The drivetrain should hold up fine for moderate off road use. These things have light duty parts but they are under a light vehicle so are a good match. The biggest problem I always have is the low stance so you have the right idea to get a lift under the truck first. These things are extremely maneuverable (especially a 2-door!) so they can get into places and around obstacles that the larger trucks can't. After clearance my second concern is traction: the stock front struts don't have much travel and the rear isn't that great either so you can get cross-axled easily if you don't have a locker or something. If you remove the front strut you'll see that it actually has a decent amount of travel, but the factory suspension design makes poor use of it - strut spacers (like Jeff's) and/or OME struts can help this a bit.
Jeff's kit gives you 2" of lift, OME springs give 30mm (1.2"), and calmini has a 2.5" kit that seems to get mixed reviews. There are some body lifts too if you're trying to fit in bigger tires. Careful with going too big on the tires though unless you're willing to re-gear the axles. It seems like a 29" (235/75/15 or 225/75/16) is popular. I've got 27.5" (215/75/15) and I'm not willing to go larger than that with my little 2.0L while I'm still daily driving the car.
Lifting the rear end is easy since it is a solid axle, but the front has some challenges. If you go too high, you need to lower the front diff to keep the CV angles happy. With the MacPherson strut front suspension you can only adjust toe in/out on the alignment easily. When you lift it you may need camber bolts to get things back in line. OME struts are designed to work with their springs that give 30mm of lift so they keep the camber in alignment with the small lift. Calmini's replacement control arms do the same thing for their 2.5" lift. Rocky Road's kit needs the camber bolts. I think you need the bolts with Jeff's kit but someone may correct me here because he has a strut spacer which may actually correct the angle - I'm not sure. There are a bunch of rear shocks that give more travel, but only the OME front strut has more travel than the stock ones as far as I know.
You asked about using Jeff's spacers with Rocky Road's kit. This is basically just adding the 2" spacers to the OME springs so you get a 3.2" suspension lift (plus the 2" body lift). I don't know if anyone is running this but it must be close to the limit for the front CV's without providing a diff drop bracket like Calmini does on their 2.5" kit. I'm only guessing though, but I wouldn't think Calmini would provide extra parts just for the heck of it.
