Why not do them yourself? From a lot of the guides I've read its something anyone can do with a bit of patience and I've seen lots of pics on another forum of everyday guys redoing their own seats with great success. I'll be doing mine soon myself..
I've read to use zip ties to help get the cover tight. Apparently it makes to world of difference.
Also - I've seen pics of seats recovered over the old foam - DON'T DO IT. Spend the extra and get new foam. Otherwise the cover will look loose and saggy. Not very desirable.
Here is a site that has heaps of helpful hints on all sorts of vette related maintenance:
http://www.corvettemagazine.com/content/view/18/28/If you scroll down to the interior section you'll find help on both carpet and seats. I've been saved plenty of times by articles on that site. Bookmark it. You'll use it often!
Also one more hint: when removing the seats, I was stuffing around for ages trying to remove the rear bolts. It had me buggered how to get the suckers out. Then I realised I could simply slide the seat forward and had very easy access. This might save you a bit of "what the hell" if you're as slow as I am!!!
Lete us know how you go - and post pics!