Why don't you see if you can find a place that buys out closing retail stores. I was able to get 2.5' by 7' metal peg board pieces that came from a closed widmans store. This would work fairly well for what you want to do.
/ Advice to novice on creating a pegboard wall in a metal carport
Pegboard is fine for lightweight stuff, but maybe not for heavy saws and such. If you paint it, use an oil based enamel that will dry hard. I prefer white for reflecting light.