There's three or four places out there that I've been told recovers steering wheels (taking the old leather off and putting on new leather in OEM fashion). I found pics of the work done by Dallas Custom Steering wheel, posted by a PFF member. He had his done with a slightly thicker padding, and it looked really good. He was very happy with the results, so I'm going this route as well.
A search on PFF turned up some other very happy customers as well. So even though it's a bit costly, I figured I'd go with them (especially since the Fiero Store doesn't have any black leather GT wheels in stock).
The price he quoted me was 269, plus shipping ( I don't think that includes the discount that PFF members get, InfiniteWills was a little cheaper, and he said he had gotten a 10% discount, which comes in close to the difference in prices). When I get it back, I'll post up some pictures.
http://dallassteeringwheel.com/sw1.htm
http://www.fiero.nl/forum/Forum1/HTML/086260.html