I have the newer lux, and I always extend the hood, but I have never had it flare. It controls flare very well. If you don't use the hood...well, I don't know. It does have a rather large front element, and I would want something helping to protect it, so the one with the hood would be my choice.
1000-1250 quid sounds like quite a lot though. I bought mine about a year ago from a member of photo.net for 1500 dollars (844 pounds), and mine was mint condition of the newest model. They usually sell for 1500 dollars or less on photo.net at the Leica forum. Perhaps you could try posting a WTB ad there.