THIS! With $300.00 - $400.00, you are not going to be able to sufficiently lift your rig, due to your worn STOCK SUSPENSION. Before you go blowing money on a spacer kit (and I am assuming that you are going to do the labor yourself, right?), you need to, at the VERY LEAST, replace your front and rear sway bar links, bushings, as well as your front coils (which will dramatically limit the "lift" that you will get with spacers since they are sagging). Once you have replaced these items, then you can start talking about doing a "lift". To be honest, you really should scrap the spacer idea all together and save your money to purchase coil overs and new rear shocks and coils. Most T4R.org 4th gen veterans have gone the spacer route, only to scrap it within a year for a true suspension lift. All of that labor that I did installing my spacer kit, could have been directed at a true suspension lift instead. What a waist on my part. Remember that not only is the labor almost equal between spacers vs. suspension lift, you also have to pay for an alignment after either type. Take your time to read the suspension link that the others have posted. Then check out the 4th gen picture gallery
http://www.toyota-4runner.org/4th-gen-t4rs/1469-4th-gen-toyota-4runner-picture-gallery.html and the 4th gen LIFT AND TIRE CENTREAL pic thread
http://www.toyota-4runner.org/4th-gen-t4rs/51742-lift-tire-central-pics-post-em-up.html.
Then come back here and hit us with your unanswered questions, before you make your final decision.
Preacher