If you start hanging around rod events you'll find there are lots of glass bodies in the hobby. Are they accepted? You'll get all kinds of arguments, many of them silly, but for the most part they are. Most T buckets/track roadsters, and '32 roadsters you'll see are very likely glass. There are many more body styles that have been duplicated though. From those who are hard core prejudiced against the glass cars you hear terms of derision such as "tupperware", plastic, kit, etc. There are high quality glass cars, and there are junk pieces. The junk ones give the good ones a bad name. Kinda unfair really, because junk steel cars are still junk too.

All that being said, and having done both glass and steel cars myself, if you have the chance to get a steel car you like I'd suggest you go that way. Once you get past the body shell everything else is going to cost you the same, engine, upholstery, paint, wheels, tires, and so on. Steel cars usually are easier to sell because the audience is larger, and they bring more money typically. This is where some will say they don't care what it would sell for, do what you want. That's fine it's their dough. But if you plan to be in the hobby for a long time, and understand that it's the extremely rare cat who keeps a car for a long time, then getting max return on the money you pump into one of these toys allows you to upgrade faster/further over the years. That way, when you become a geezer, the young guys can look at what you've amassed over 30-40 years of horse tradin' and deride you as a "rich guy". So goes life.