So I cannot help w/any actual prop building (I am SOOOOO Interested in doing it, but am very intimidated), but for the paint part, I used a site recently for my car actually. It is called
Touch Up Paint from PaintScratch.com
You can enter in Vin numbers even to get the correct paint match. You can buy your chosen paint in 32oz cans. I do not know at all if it is more cost effective to buy them from this site or from an auto painter directly. But I can at least confirm that they do good work. I had to order Volkswagen Black Magic Pearl in pen size, and it looks great. Spot on. Of course they sell all the other accessories too such as primer, clear & body filler & rubbing compounds. But you should really only need the paint.
Actually, it looks like they have a flat rate sheet. Hang on.....
Basecoats
12.5 oz Spray can: $24.95
Pint: $90.70 (seems kind of silly that 12.5 oz in a spray costs $25, but for an extra 3.5 oz not in a spray, it costs an extra $65.75. You could buy 2 cans for less than that)
Quart: $132
Gallon: $347
So I am not sure if it is more cost effective to buy from these guys or not. But just so you have the option, they do make them in larger sizes available to the public.
Paint code AX5 comes up w/Nissan Murano Red Pearl Tricoat (Man, I guess being a Tricoat/Basecoat/midcoat, it is much more expensive). Well either way, I just wanted to supply another option just incase. Who knows, it may be a great deal. (Probably not though). :facepalm
http://www.paintscratch.com/neworder/index.html