Last summer, shortly after I got my KJ, I put in Rocky Road Outfitter's budget OTT lift. It was fairly cheap; about $350 w/ shocks. Now, I get to replace the upper control arms and lower ball joints. I'm also taking out the OTT kit and replacing that with longer struts/springs from Rusty's OffRoad. That lift kit is also fairly cheap (about $100 more than RRO's budget) but, since I bought both and some other parts that got damaged by not having done it right to begin with, the total cost is somewhere near $1000 dollars.
Now, I'm not saying that the OTT spacer kit won't work but, in order to make it work and not destroy other vital components, you have to limit the distance that your suspension can travel, which imo is not what you want to do if you're trying to make a trail-ready vehicle.
Now, having said all that, I should have an used OTT budget lift kit for sale for VERY cheap as soon as my UCAs get here. (very cheap, as in; you pay shipping, it's yours) I'd even be able to throw some new, unused shocks in for a little more.