I've seen both used before on many builds here...it comes down to availability....
8.8 is almost a 9in...
blazer is smaller..8.5 I think..
8.8 with disc brakes and lockers are common..
not sure on the 8.8 ratios..
a zr2 rear has 3.73s and locker with disc and is 3in wider than a standard s10
Just for cruising either would be fine..it just comes down to what you can find...
Also think about the ratios...tire size,trans with od,gear ratios all play into making a good cruiser...
Use this calculator....
http://www.csgnetwork.com/multirpmcalc.html
I use the fill in the blank at the bottom and itll show what you will get..