I put Downeys and new shocks on my '95 (2nd gen) in one afternoon/evening.

Downeys:
I used the heavy duty springs (1.5in longer) plus 1.5in blocks and spent pretty close to the same prices you're looking at, ordering from Downey.
What I thought was going to be 3 inches of lift on the rear actually gave me 4.5 inches of lift, evidence that my stock had sagged 1.5 inches in about 8 years <img src="/forums/images/graemlins/butwiggle.gif" alt="" /> (I replaced 1995 springs in 2003). The heavy duty springs are the same price as the light springs, and do _not_ make the truck ride rough. In fact, my girlfriend who is a city girl, would rather ride in my truck than her car, if that tells you anything.

Front Torsion Bars:
Unless your front sags, don't bother. My front wheelwell trim is within 3/4 of an inch of the back, or at least it was when I did the springs. I haven't measured since then but it doesn't seem much different.

Shocks:
The only downside to ordering everything from Downey was that I ordered shocks through them, which delayed the order several weeks until they got them....then the shocks busted very quickly and I ended up going with Ranchos 5000s. In short: don't go with Doetsch Techs, the shocks Downey recommends.
Rancho 5000s do have the problem of being made for a smaller-diameter stud than the 4Runner has, but I knocked out the rubber bushings and put in the bushings from my old shocks. You may be able to drill the new bushings out larger, but as I recall, it was easier to reuse. The Rancho 5000s are a little bit longer, so I wouldn't use them if you don't put the 1.5in. blocks in with the springs.
Some time after I put Ranchos on the back, I decided to replace the front shocks as well, and went with Monroes from Autozone. No problems so far, they do everything I coudl ask for.

Good luck on your suspension.