I have been installing a lot of 6 lamp t5 hi-bay fluorescent fixtures in factories and shops like yours. Just guessing, you will need about 10 fixtures for your shop. They cost about $125-150 with bulbs
I have 8' double flourescent fixtures with cold weather ballasts. The cold doesn't bother them, but if it's cold AND damp, sometimes it takes a few flips of the switch. My shop is 24 X 28 with 12' ceilings. I have four fixtures.