97's seem to already have the thicker wire instead of the cheaper thinner wire that gm started to use and save money with on 98+ cars. So a rewire kit shouldn't be needed.

I guess you'll just have to see what the car does. You may need injectors, you may not. If they end up running static then yeah you'll want them. But I don't see a huge increase in fuel usage by doing the mods you want to do.