Having owned a Speedway '27 body I'll say they are not the best quality available. Don't have any personal experience with TP.

Two other companies have a very high quality standard, and make the '27 body in glass. The first is Poliform http://www.poli-form.com/index.html . Not only do they make a body, they also have a stretched compartment version for more comfort. If you're over 5'9" they start getting tight quick. They also make a complete track roadster "kit", probably could be adapted to a flathead. The other manufacturer of excellent bodies is Wescott, http://www.wescottsauto.com/ .

Probably a good place for you to start doing some research is to get Street Rodder magazine, they're loaded with ads and lots of them are chassis manufacturers.

Also, ebay will ocassionally have original bodies available. Condition is all over the board, and most don't have titles. You'd probably have to buy a complete car to get a nice body and a title unless you're very patient.