HELP with bodywork

It would be with a proper 2K high build primer but I can't say if the spray bomb stuff will fill 120 scratches as effectively. I spray 2K over 80 grit with no problems and then block with 220, 320 and final sand with 600 wet but I don't usually shoot a sealer so if you do 400 may be ok to finish with. You'll have to ask your painter what he wants it to be final sanded with. In fact get everything in writing and I mean everything, what products he will use, what he expects you to do, all of it. If you end up with problems you'll be happy you got it all in writing.