I am in the process of going through the same. I have OSB on the bottom 8 feet and metal above that. I am going with glossy white on the OSB and the ceiling is white. I considered gray on the metal part of the walls to break it up but ended up going white everywhere.

I researched the paint options a lot. Ended up with Sherwin Williams Pro Block primer and Sherwin Williams water based alkyd urethane. It is more durable than latex and really did not cost me much more than good latex paint would have. I ended up going through a Sherwin Williams commercial store. I needed 15 gallons of pant.