Kirbans doesn't sell the GNX style wheels anymore. The only place to get the GTA wheels is from Classic Industries. You can order them through YearOne, but they order from Classic then ship to you.
C.I. just got a HUGE shipment of GTA fronts in, so snag them up now before they are gone for another year.
And instead of buying the set (cheaper), buy the four fronts. That way you won't have to fiddle with spacers. I know that some guys run the rears up front and fronts in the rear. It does work with some. The choice is yours, just making a suggestion.
P.S. Don't forget to order the platic lug covers and lug nuts. As well as, the center caps and medalions. You can get Buick medalion stickers from the various venders out their.