It seems my best options are the Bessa R or Canon 7.
Apart from age, how do people think they compare?
I'm assuming that you are looking for the excellent value for money that can be had using LTM lenses.
The original Bessa R is modern, handles very well, and has a wonderfully clear finder. It is the only LTM camera ever with a behind the lens meter. But it screams of plastic, so is not for the borderline Luddite.
The Canon 7 is larger and heavier and is built like a tank. It has a pretty good selenium light meter. Its finder is not as brilliant, but you can select framelines for 35, 50, 85, 100, and 135mm lenses.
The Canon P is a stripped-down 7, with no light meter and a finder that displays 35, 50, and 100mm framelines all the time. It looks considerably less clunky than the 7, and typically costs more than the 7 on ebay.
You can always buy one of the newer and more expensive Bessa R-somethings, and stick an LTM-to-M adapter ring on it.
The Bessa T doesn't have a finder at all, so sort of defeats the purpose of having 35mm frame lines.
In my humble and not very objective opinion, I would buy the Canon 7, and get Jupiter 8, 9, and 12 lenses.
I think the Canon vs Bessa question comes down to whether you want modern features in plastic, or the best 50-year-old technology in brass.
Cheers,
Dez