I’d go for mid-grey floor paint myself, but my step-father prefers a lighter colour. He does like his garage to highlight dropped spanners and oil though.
Racking/shelves can be got from B&Q for cheap money. I got 4 lots of their four shelf plastic rack for my garage and they hold a lot of paint and random stuff. They can also be linked together and have brackets for attaching to walls.
Re a bench, see if you can blag some off-cut kitchen worktop from a DIY shop. it’s good and solid, you can attach it easily enough using angle brackets and batten and it’s strong enough to take a bench vise. Plus, you can sometimes get a nice pattern. Also, formica wipes clean.