By street scraper you mean like a low rider truck right?
I am very very familiar with S10s and lowering them both static or with air ride. (Never actually had one but my father had a C10 as did my uncle and I always wanted and studied "mini trucks")
I believe these trucks have torsion bar front ends correct?
If so you could probably lower it quite an impressive amount just by cranking that LCA bolt to the left!
(I lowered my Valiant this way)
Only side effects may be bottoming out on the bump stops but if you've ever driven in a lowered static truck you know this is the very least of your worries
That being said you did mention bags. Bags are possible to set up on both torsion bars and coil spring applications. Torsion bars may just require some fabrication of custom mounts, and you would most probably replace the front shocks with just the air bag its self (when aired up you'd never be able to tell the difference)
As for the rear end I'm sure someone sells a 4 link for the D series trucks. If not "Air over leaf" kits are very cheap, reliable, and dumb easy to put in.
Hope this helps!