You mentioned a TLR with a couple of lenses, this sounds like you are pointing towards a Mamiya C series camera. I've got a C220 and C300, they are both great cameras, with some fantastic sharp lenses although I do find them a bit prone to flair if I forget the lens hood. I wouldn't really call them small and light though. I do happily carry them around in a bag all day but they are still a big box and a couple of Kgs of weight.

If size is an issue, I would suggest the C220, rather than the C330. The C220 is appreciably lighter and slightly smaller in the hand than the C330. The benefits of the C330 are really only three that I can think of. The auto shutter cocking makes no real difference, I still cock my C330 by hand as sometimes the 55mm lens misfires whilst cocking so I don't take the chance. The parallax correction is nice but nothing you can't work without, the C220 has fixed guide lines which aren't quite as convenient but are not hard to work with. The only reason I've kept my C330 is the interchangeable focus screens. I do lots of landscapes and I like the grid line focus screen I've got for the C330. If you are doing mainly street, or are better than me at judging a horizontal than me, it isn't necessary.

Having said all of that, have you considered a MF rangefinder like the Mamiya 6 or 7, or Bronica RF645? You get a range or interchangeable lenses (some of the best in the world with the Mamiya 6 and 7). They are significantly smaller and lighter than a TLR, especially something like a C330 and street and travel is often seen as the natural home of the rangefinder camera.