I have a Spotmatic F, they are great cameras but a touch noisy by later standards, I also have a Leica M3 and fouind I used it un prefeance.

You need to think about size and weight, do you want an SLR or a rangefinder, an M3 in decent condition is going to be ouitside your budget range. You should be able to get a Spotmatic F + f1.4 lens for about $200.

Ian