Suspension question

[stingray72]

I'm going to replace the springs and shocks on my Jimmy and take it back to original ride height (maybe a 1 or 2" drop haven't decided). I'd eventually like to get 20's under it so I definetly don't want to lower it too much and have them not fit.

Will 20's fit under with any sort of drop? (picture would be nice)
Where would you buy your springs and shocks? I've searched the vendors and most everyone seems to be priced pretty much the same. Are there differences in springs? Forgive my ignorance. Just learning

TIA