I used Powdercoat on the main pieces. Used factory color matched paint and a hardner on the vents. Came out pretty good I think!!View attachment 283584
If it was me, I would choose powder coat, or normal rattle can paint. Probably just some rustoleum semi gloss black.
Not big on line x, I don't like the rough look an the stuff tends to hold onto dirt more then a smoother paint.
Floor boards, line x wouldn't be bad.
inner fenders are going to get dirty all the time, so I would think just all black with a paint that's easy to clean up. My 2 cents