Ivan, I'd second the recommendation to hold out for an R2. Not only do you get an M mount, but reviewers universally praise the sturdier construction of the R2 vs. the R.
I have a T, but I got it to use with my 21mm lens, for which no rangefinder had framelines at that point (though the R4A will). I use "universal" finders with cameras that don't have framelines, but things are a lot easier with a combination viewfinder-rangefinder.
The only other consideration is the longer rangefinder base of the T, but unless you plan to use a 135mm lens or a fast 90-100mm a lot you should be OK with the R or R2. (For my 40/2 and 90/2.8 lenses I use my CL; usually I keep the 21 on the T, but if I need to, I can always put a 135 on the T and use my Soviet "turret" finder. It's a stopgap, though.)
There have been several R2's in the classifieds lately... There was even a "user" one a while ago, I think.
-- Michael