Matte white will show the dirt bad. Go gloss.
my bandit has the front dropped by 35mm with USD forks and the back raised by 35mm and its not unstable at all. its quick steering but only on par with a cbr600 now and it hasnt tank slapped...it was make it quick steering but 40mm shouldnt make it too unstableYou need to find a way to lift the front as well or the bike is going to become unstable
I took the parts to Tattarsuo (not Eleko, heard that they are bad) i'll see what the parts will look like after coating and decide if i want to return. But 80-100€ including sandblasting (important parts protected) didn't seem too expensive for Finnish standards. However, they don't do metallic red powdercoat (for the rims and covers) so if you have a place in mind that does, i'd be happy to hear it.Where are you planning to do the powdercoat and what kind of price range are you looking at? I could throw in some recommendations as well as an option: look up Cerakote ceramic coating. Much tougher, more color options and not that much more expensive.