The top 2 online car selling sites would probebly be:
http://pages.ebay.com/ebaymotors/
and
http://www.collectorcartraderonline.com/
Of course there are many many more sites, but these 2 seem to have the most classic vehicles for sale, and are very current. Getting thousands of new cars listed every day.
But as always, when buying a car online before seeing it in person, it's best to use a inspection service prior to purchase. It could be the best 400-500$ you've ever spent, saveing you from a potential lemon.
I have purchased cars from both ebay and classic autotrader and I had no problems with either service.
And one last thing, if your looking to buy a 67 fastback, you should expect to drop alot of money for one. The 67/68 fastbacks are quickly becomming scarce because there are lots of new car companies buying them all up and useing them to make gone in 60 seconds gt-500 eleanor clones. I think there are currently 5-6 majior eleanor clone companies out there right now, and since fastbacks are more rare then coupes, and these companies are buying them all up, it's supply and demand. So naturally the price of 67/68 fastbacks has skyrocketed. I'v seen some terrible 67 fastbacks covered in cancer, with litterally no interior, no engine/tranny, no floorpans ect... sell in the 4k+ range. And the mint condition fastbacks are in the 20k range. So for a decent condition fastback, expect 10-12k. Unless of course you wanna do a ton of cutting/welding work to the frame/body, then buy one of the basket cases for alot cheaper.
This might sound like alot, but remember that these cars are only becomming scarcer and rarer, so the price will only continue to climb, so you might as well get one now before they go up any higher.
