Sounds like a good idea, this is something I plan on trying for my car.
Thin plywood sheeting will probably be the best thing to use for the template.
Most car part stores offer fiberglass repair kits that are fairly inexpensive if you dont have too large of a project. One drawback is I've heard it can make quite a mess.
Then after you are done you can get some vinyl, or other fabric to cover it.
My console will mostly be made of particle board or MDF.
Particle board is cheap and easy to round off and smooth edges. It might be an alternative to fiberglass if you dont need a really curved surface. Then just cover like everything else.
Good luck, let us know how it goes and maybe some pics. I really like people who take the time to make their system look good as well as sound good.