Not a bad score at all. As stated above, SC430 wheels will fit no need for spacers or longer studs.

Seats, you have 3 options;
1. Junkyard, 90-92 seats are plentiful in many colors, black, tan, blue, red, there might be a dark brown in there too, some colors available in cloth as well. The trick will be finding them in good condition with no tears, especially the leather ones.

2. Have a local shop redo the upholstery, if you have a hookup this is the way to go.

3. Buy a re-cover kit from leatherseats or someplace similar, they will sell you the kit which is cut and sewn specifically to fit your seats, you remove your old leather and install these in their place using hog rings and such. $600-900 ish? They seem to always have one kit on ebay with a low starting bid but not sure what the reserve is.