You're getting a lot of interesting suggestions. If I'm reading you correctly, I think you're curious about what Leica imagery at its very best is all about. It's possible to experience this without necessarily breaking the bank. An M2 or M3 in good condition and the latest 50mm/2.8 Elmar-M can produce images which are about as good as one can get from Leica equipment, and the cost should be reasonable. (Moreover, the M2 is prettier than the M6, and the Elmar-M is seductively retro-looking.)
Of course, a IIIf and an Elmar 50mm/3.5 would be an excellent, inexpensive kit, but it would involve sacrificing some convenience in use and a slight (but noticeable) loss of contrast.
I agree with others that it might be a mistake to sell everything and switch entirely over to Leica, but of course that's your decision to make and really none of my business.
Richard