Dave,
You might have seen my other thread under the mods section where I just put one on my 69. Some think it is kind of Rice looking, but that is okay. Obviously it would not be the best "look" for your car.
However, let me say that the mods I did to it to make it fit the Shark will be about the same no matter what you do if you find a generic custom wheel that you like.
Do you have tilt/tele?
If so, pull your old wheels off and make a paper template by tracing through the center hole and mounting holes. Make a copy or two of that and cut it out.
Take your new to you wheel and center the template. Using a 2" hole saw, cut out the center, then drill the outer ring holes. With a dremel you can take care of the last minor details. Now, you can bolt it on your car and reinstall your stock horn bezel for a finshed "Vette" look.
I have seen custom wheels in the local autoparts store for as low as $79 which are much smaller in diameter than the stock Shark wheel.