Chris : From seeing those pics, I'd guess you are pretty much undersprung (mostly up front) AND undershocked (all-around) for what you're trying to do there. Swaybars are nice, but they aren't the cure-all either [img]smile.gif[/img] .
And yes, you'll notice that the car oversteers more with the GW rear arms (conversely, requiring less rear bar) than with any of the other arms available. This is mostly a function of the bushing design. A better posi (i.e. Torsen) also accentuates this.....you'd be surprised how mild my rear suspension setup (springs/bar) is now!