Actually, yeah, I had to word it just right in a google search, but I did find an Autometer gauge with adjustable ohms from 0-280.
THIS would be perfect. I wasn't finding any other gauges that were full at 4.3-5.8 ohms and empty at 78.3-84.8 ohms. I called Autozone, they carry it at a price of about $117, but to have a working gas gauge, I suppose it's worth it, right? Just gotta save up now. Thanks for all the input, guys, especially to G6CivicX for the ohm readings at empty and full. Helped narrow things down a lot.