I don't know about other amps and the fuses, but my JCM 900 has a fuse for each power stage or something, so if one of the valves dies, it can still run on half power. So if it cut out in a gig, all should be fine.
Other than that, erm, methinks a JCM 800 is what I am wanting, just with this fuse thing, and some kick ass power scaling or a good attenuating thang so its manageable