Some other items that may interest you. This sway bar seems pretty nice, a little pricey as compared to others, but online with SLP and RAT.

eBay Motors: 97-03 Pontiac Grand Prix Addco Front Anti Sway Bar GTP (item 300268606854 end time Oct-31-08 12:48:09 PDT)

And these rear trailing arms are something I am very seriously considering over the GMPP trailing arms.

eBay Motors: 97-05 Grand Prix Regal Monte Carlo Rear Trailing Arms (item 200266934031 end time Nov-22-08 08:31:04 PST)

You can find another brand, BMR I believe on PFYC's site for our GPs, and they actually cost more than these guys. And these, like the BMRs come with Poly gaskets to help firm up the handling too