Go w/ a spool.
If you're on slicks, ET Streets, or any other type of tire that has hardly any tread on it...IT DOESN'T MATTER WHAT TYPE OF DIFF. YOU HAVE when you're on wet pavement. You will spin out just as easily w/ a suregrip as you will with a spool. It's the tires that matter, not the diff.
I've logged a bunch of street miles w/ both suregrips and spools on both normal street tires and drag tires on wet and dry pavement. Unlike a lot of people who always chime in on this subject.
A good tight suregrip unit, whether it's a stock mopar unit, a locker, or whatever, will spin both tires equally on wet pavement just like a spool b/c you're on a slick surface.

The only thing I noticed different on the street is turning at really low speed takes a little more effort. Other than that, it drives just like anything else.
I've never experienced or even heard of the car wandering after letting off the gas at high speeds...unless you were on bias tires w/ too low of air pressure. Again, that'd be due to the tires and not the diff.