could someone tell me the best paint and underseal to use on my sierra shells. both will be in bare metal by tomorrow night inside, underneath and outside. they are being sand / soda blated tomorrow so need to get protection on asap. some areas will need repair so primer will be put on just for the protection. any advice would be very welcome as i'm sure there will be a few on here who have done this. i want to try and do everything myself as far as possible. top coat will be 2k diamond white.