Clone market is all about color. It doesn't matter which direction you go in concerns with RT or TA. It mainly matters that you end up with a show stopper color combo. Black always seems to bring the big money on muscle cars. I'd go black RT, black vinyl roof, window louvers, black tail and hood stripes, white interior, with a nasty 440 6 pack. I would go high impact, orange, plum crazy, panther pink, with a T/A. I also agree with the guy who said you should stay more true on a TA clone and you can be more liberal with a 440.
If you watch the real cars sell, T/A's tend to bring a little more money then RT's. That doesn't mean that there is a direct relationship to the clone market.
A 340 is better to get out a drive, the 440 impresses with it's horsepower.
I personally am looking for a 340 or 383 car to get out around town in cause I already have the 440. The reason I bought mine, nice car, right money, and close to home.
Producing a nice challenger period should be the main objective.