I installed 1 3/4 inch spacers on mine and have had zero issues. Stock ride height and stock 20's.
Check my thread out: http://www.ramforumz.com/showthread.php?t=91108
I wouldn't suggest the spacers that you slide on, from what I heard those types are BAD. Click on my thread above and in there is another link to where I got my hub centric spacers. Now, if you do not plan on cutting your stock bolts then you will have to go with a minimun of 1 3/4 inch spacers...otherwise you have to cut. The spacers I have bolt right on (use red locktight!!!) then once they are on you put the wheel onto the spacer which has new bolts to lock down the wheels.
I would start by clicking the link in my thread and calling them. The dude that makes these knows alot about what to do and what not to do when it comes to spacers and is more then helpful. He may have a better working solution to your problem.