If rangefinder type manual focus is important I'd suggest looking at the Epson R-D1 as well as the M8, it's a bit cheaper, and gives a smaller file, but the jpgs are pretty good.
I'm not so sure about the newer EVF bodies for manual focus. It works, but there's differences from rangefinder focusing that may require new skills to be mastered, and aging eyes may appreciate AF.
With newer bodies, AF lenses might be a better option. There's lots of excellent options out there now... X1, X100, X-1 Pro, E-M5, Nex7...
Just don't go a body that requires using the rear LCD to compose/focus. Speaking from experience there is an age that you reach, where your arms aren't long enough to focus on that screen A nice eye-level VF with diopter correction is what you want.
+1 for Leica X1, this is a perfect gift for your old man.Have it only for 2 weeks, I am stunned by Elmarit 24mm clarity and color, very friendly, if you want to explore more as a Pro , it also has raw file DNG.Have it in your palm this is an art piece, and it has attractive force to everyone goes by.
I was going to mention the X100 or X-Pro 1 until Ricardo mentioned that a lack of a proper scale on the lens was a major failure. That cuts out a lot of auto focus systems. Maybe all compact autofocus systems? Some implement an electronic depth of field scale (X100, X-Pro 1 as examples) as an overlay in the viewfinder.
If you revise the requirements and end up leaning X-Pro 1, don't forget you need to purchase a third party optic for the viewfinder for diopter adjustment, if required. The X100 has one built in, as do the NEX, GXR and many others.
Between the M8 or R-D1 I think I'd go M8 for a more modern sensor but also out of fear (perhaps unfounded) about serviceability of the Epson going forward.
Or one of the micro 4/3's auto focus cameras known to do a very good job at focus and JPG production? Might not be what you started to look for but perhaps is the right size and tool for the job?
A nice eye-level VF with diopter correction is what you want.