Cutting Holes in Sheet Metal

I had new floor pans put in the wagon and as such I lost a few holes in the toe board/firewall along the way. I need to cut/drill a couple of good sized holes for the back up lights harness and the speedometer cable grommet. Is there a single reasonably priced tool I can buy that will let me drill relatively large sized holes of various sizes? I hate to drop serious cash for monstro drill bits I’ll only use once. I have a few hole saws, but they are made for wood not metal, do they make hole saws for metal and if so can I get them at a typical hardware store?