That would be the LX with K30/2.8.
I like aperture priority for fast shooting and compared to the ME (super) it does have a DOF control and aperture reading in the viewfinder, which I would both appreciate if I had to use only one body for 6 months. Plus most shutter speeds are mechanical. Do like to use the K55/1.8 but I think I would start to miss a wide angle after a while.
The other option, K-mount but not Pentax;
Revue Solar 100 with Revuenon 55mm f1.2 (a lens that is at least as good as the K50/1.2). No need for batteries at all, it has a solar panel for metering