You can travel much lighter and smaller with the Pentax MX - here shown with the Takumar fisheye. Wait till you see the biggest full display viewfinder in any SLR!
Actually my personal choice for travel is the Olympus OM-1n but I like where you are headed with this. I have a Spotmatic kit with a bunch of SMC Takumar glass and always thought in the back of my mind, get a MX put an adapter permanently on and just run with M-42 lenses.
"Life moves pretty fast, if you don't stop and look around once and a while, you might just miss it."