I'm in dire need of some sort of amp I can transport on a flight, now, if I bought myself a head, I'd have to get a flight case to guarantee it didn't get smooshed, so my approach is to find a rack mountable guitar head, much like you can get rack mountable bass heads.

Anyone got any reccommendations on that? I ask this cos I only just realised, Line 6 rackmountable POD series units don't work as amps in themselves.

Well if you are thinking of using a POD you can use any solid state power amp with it - the POD is a 2u rack and so are most power amps. I can't think of any specific brands off the top of my head....
However if you are talking about buying a flight case for a head thats about £100-£150, but a 4u rack case is going to be at least £50 and then you have to pay for the power amp you are looking for, a preamp (EG the POD) and the cables. If you already have an amp head this would appear to be a false economy.
If you don't have either I'd recommend buying a real amp head purely because it sounds infinately better for metal.

This was just for convenience purposes. The idea of getting a solid state rackmount guitar amp was so I could fit it in my rack case with my bandmate's module, and not need a power amp. But it looks like the issue's solved as I'll be borrowing a guy from this other band's amp.