New Idea or old???

[XR650RKing]

Hey all...I'm new here but found this site while looking for blazers for sale and was wondering ya'lls opinion on what I am thinking...First why I am thinking what I am.

I want a 4wd but rust is so much an issue with these and it seems to be in the 4wd b/c offroad dirt holds water to the spots and promotes it...I was thinking about looking for a 2wd in good shape and then a $500-$800 4wd parts truck (blazer or pickup) for the drive-train???? Since I can rebuild the drive train w/ less worry about rust?

Ok to those out there that know more...what is the fesibility of this in;
..cost of my idea vs cost of good shape 4wd,
..or that my assumption that 2wd's are more likely to not have rust?

Thank ya'll for the time
JT

PS I can't find my interchangeable guide :-(