if you plan on more power at some point and/or tire roasting then the 8.8 ford is a better choice because it is stronger. they are available from an explorer but will have the centre section offset to one side. if you already have some stuff mounted under your truck then that may interfere. there is an 8.8 in a mustang with a centred center section though. they have drum or disc brake set ups. you would have to cut the old suspension brackets off so you have a bare axle tube and then weld on your own mounts for springs, available at a spring/trailer axle shop for cheap. you would also have to redrill the axle flanges for your wheel bolt pattern and install chevy sized wheel studs but that isn't a huge deal either. if you get an 89.8 from somewhere try to get the rear part of the driveshaft as well because they are a flat flange yoke that mates to a flat flange on the driveshaft which houses ther ujoint. there is a regualr yoke availlable for a normal chevy style ujoint I believe. also grab the park brake cables and their centering link.
one thing to watch for is the size of the disc rotors so you will get the right bias front to rear. also you need a disc/disc master cylinder if you go the disc front and rear.
there is really nothing wrong with drum rear brakes if you already have drum set up on the camaro axle. the brake bias is more brakes on the front than the rear anyway.
I went the same route as you, got an s10 rear with discs etc, mocked it up, found it was too narrow for my likings. sure, a huge offset wheel could be used with more stress on the wheel bearing and axle. research found they are not as strong as I thought. sold it.
went to the camaro diff. had the disc brakes etc.mocked it up then researched and found they aren't any stronger than the s10. sold it.
looked for a 12 bolt truck axle from late '60's. found not that readily available and also usually only have drum brakes and need a total rebuilt. was stuck on disc rear. scrapped that idea.
cruised through pick n pull with a tape measure. went with the 8.8 from an explorer. 3.73 gears, posi, disc brakes, big axles, easy park brake connections, offset wasn't a big deal for me. will re-bearing it later when the truck is near completion. redrilled the axles and discs for the chevy pattern and installed same sized studs as the front. would have gone with the mustang 8.8 but didn't find one that day.width is really close.
for more info on the 8.8 go to
http://www.therangerstation.com/tech...8_8-axle.shtml
there is a full article on the 8.8, what it came in, how to mod for hp, how guys take the offset and narrow the housing on one side for a centered section using stock axles etc etc. if you go to the home page there is more info
if you are doing it on the cheap, like me, then a trip to pick n pull may reveal the camaro parts you need for stock rear disc as well. maybe need a whole new axle but that won't break the bank if you have time to cruise the yard, or craigslist or local parts store classified board. grab the master cylinder as well as the park brake cables etc