I work in a body shop, and a few years ago, I worked for a paint store. Most exterior paint sold by non-jobber paint supply houses are little 2 or 3 oz containers with a little touch up brush. The EPA doesn't worry about these, because the quantity is small. Interior paint will have to be sprayed - so this may require a reducer and maybe a catalyst of some sort, depending on the type of paint. Interior paint is tough because there is no good paint code to go on.
Your best bet is to find a "jobber", a place that sell paint to body shops. Get them to check a chip book and find the color, and mix the paint.
If you can just spray it straight from the container, you can buy a "prevail" spray pack - a bottle with a aerosol can attached to it.
The interior trim will have to be thoroughly cleaned with special solvents, and prepped to make the paint stick.
You may want to try to see what a body shop would charge to spray it for you.