Disclaimer: I have been wrenching on my vehicles for a long time and just about anything short of serious engine work is in my wheel house. So take my assessment with a grain of salt.
Installed the one on my truck at the top of the page the other night. Nothing other than some basic hand tools, a floor jack, hammer and some jack stands. Ratchet wrenches make the upper strut bolts a breeze. Did one side at a time. 3 hrs start to finish with a dinner break and I wasn't in a rush at all. Just go get an alignment after for $80 and save some coin on the install. Its an easy project. Have a 1/2" electric impact and you can cut some serious time out of the project.
Follow MotoFab's directions and it goes smooth.
There are a few little things that I will scrutinize about the kit, but its just nitpicky stuff. I would still recommend the kit to any K2xx owner.
1) The 2.5 kit that uses only an upper spacer is intended for you to install the strut 180* from how it is originally placed in the truck. (I assume any of their upper spacer only kits are the same) In theory this should work, but the lower shock mount is clocked about 10* to match the angle of the lower control arm at standard ride height. When you re-install the strut 180* out, the angle of the lower mount does not align with the upper and you have to push the strut back into the tower AND jack the control arm up at the same time. Kind of cumbersome, but not a big deal. Just annoying. If I did it again, I would just pull the front end apart and switch the struts left and right to solve that problem. From looking at the part numbers, there isn't anything special about valving or spring rates as far as I can tell so it shouldn't affect the truck one little bit. I could go into a whole thing about shock/strut placement and angle, but at the end of the day, for a street truck that occasionally sees some dirt, no big deal, so I wont over-complicate it for the masses.
2) The upper strut mount hardware they supply is specified as 16mm, mine was 17mm. No big deal, just a different socket.