Re: lower unit paint
Are you covering over paint? or painting bare metal???? If painting bare metal you're advised to use a "self etching" primer. I used a Chromate paint, which is said to bond very well with bare metal. If you're painting over paint, I don't know that it will make a big difference other than cost, appearance. I'm probably not the best source of advice though , as mine is getting shots from 5 different colours of super flat paint for a Camo scheme. I do have 2 coats of zinc chromate, and 2 coats of filler primer as a base though. Good luck.