tiksie, wish you were in melb!

I need a few tips. I've got a front bar (OEM, plastic) and front lip (polyurethane) which I need to strip, sand and prime. I'll then take them to a panelbeater to get the final spray done as I want a perfect finish and don't have a compressor at home.

noob questions (haven't done much spraying in the past):
1) is acetone an alright thinner to be wiping down the panels with before each round of sanding?

2) what sort of primer do I need? these parts are plastic/PU which means the paintjob needs to be able to handle small amounts of flex from bottoming out etc. Do I need to use a special plastic primer, or is the K&H primer from autobarn ok, or do I need to use plastic primer, THEN the normal primer? tips here would be great as I don't want the paint cracking if I scrape the front end on driveways etc.

3) also, do I need to tell the panel shop to use any additives in the paint so that it's suitable for use on the flexible plastic surfaces?

Thanks in advance, and great thread