If you're bringing back a car from the junk yard, I hope you didn't spend too much on it. A car's value decreases over time, and the rate of that decrease is dependent on where it has been housed and who has been taking care of it. A car that doesn't run is not worth more than 1000 dollars, unless it is an extremely rare model. Any car with signs of rust shouldn't be worth more than 5000 dollars.
Junk yards often have poor conditions for car bodies, due to exposure to the wind, rain, and sun. If you want to find a good project to work on and restore, you're going to need a car body that has been kept relatively protected in an open air garage or in private storage. If you are up to the challenge of a rusted, wet, dented body, you can open up your options considerably.
While the motor itself doesn't play into the style of the car directly, it does dictate the value of the car considerably and will ultimately be responsible for the car's performance. If you are going all out on the body style, remember to put in the right engine, preferably a powerful V8 for a sports car or truck. Smaller vehicles can perform with a V6 where necessary, but will have less value.
Be warned—cars that draw to much attention to themselves are targets for vandalism, damage, and theft. This is not an issue if you are smart about parking and storing your car. Never park in dark areas such as the backs of parking lots and unlit streets. Keep your car in the garage, with the garage door closed. Park within the boundaries of your spot to be polite. Never park outside of the lines to take more than one space.