Easy, I got a 3.5E Planar, working meter, £400 GBP.
I sort of agree with aperture64, a TLR might not be right for you. I've had mine a week or so, and I'm yet to be convinced. Whilst very portable for an MF camera, I do find it odd to use, and not sure I'll get used to it. Conversely, when I got home, I had a play with the M3, and it feels extremely natural in comparison.
I probably second the meter advice too, I was hung up on getting a meter, but in reality, even if it works, how accurate is it? Also, handheld meters are cheap and easy, or if you shoot negative film, just shoot sunny 16.
On the plus side, if you like how they work, they are beautiful cameras, portable, not that heavy and very distinctive.