Rob,
You are right about the four-speed - a much more brutal launch, which can shock that rear suspension into massive hopping. With the boxed arms, polys, and no-hop brackets my Chevelle runs a 12.98 @104, no sign of wheel hop any more (although it is an auto).
I believe it's important to "tighten up" all aspects of the rear suspension, and the boxed arms and poly bushings go a long ways to accomplishing that. I wasn't too thrilled about drilling my housing for the no-hop kit, but I was definitely thrilled with the results. That kit relocates the upper arm rear mount upwards; the good news is there are also BOLT ON brackets that relo the lower control arm rear mount downwards to achieve the same effect. This is a very common traction trick on fourth gen Camaros.
BMR Fabrications
http://www.bmrfabrication.com/A-Body.htm USED to sell these brackets under part number CAB-004, I would give them a call and see if they have any around (picture attached). I also put in the air bags, then took them out as I didn't like the street ride (too much rear bounce). But there is nothing like a passenger side bag to keep the chassis square on launch. Here are a couple of set-ups that have worked for people.
http://www.chevelles.com/racing/tricks.html
Hope this helps!
-Sam