All the gauge sets are available in 12-volt or 6-volt, I bought a fuel gauge from ClassicParts.com which failed very quickly. I think most people just replace the bezels because they are pretty cheap. On those I bought them from the same vendor and they have held up well. Gauge sets are easy to rebuild/replace with new, a bit harder to refinish if you apply new faces etc., but not much harder. Here is good tech tip reference for the rebuild process.
http://www.stovebolt.com/techtips/interior/gauge%20cluster/index.html