Gosh Chip, I asked you if you wanted my Shankle rear bar last year ... and you said "naaah".
I sold it on eBay already, unfortunately.
1) Unless you have a pretty radical suspension (and strong mounts to boot) the rear Shankle bar will only increase your tendency to snap oversteer, not decrease understeer.
2) The GTV6 rear bar is not a bolt on to Milanos because the way the endlinks mount to the deDion is different.
My suggestion, however, is to keep the rear bar that you have now, and just change the bushings to polyurethane if you can find any for that bar.
I asked Joe Beninca last year if he recommended I change the front or rear anti-sway bar sizes and he adamantly told me to keep them as they are, and just use his springs, torsion bars and modified Koni's. You already know how I feel about the suspension!