Just to finish this thread off, and it may seem rather odd given the starting point, but I have bought a used (only once) Fostex Fr2-le.
I couldn't make up my mind about which of the four recorders I was considering was the best buy for me, and I found myself just going round in circles.
However, with more thought, I realised the need to use the recorder with the camera was secondary to getting something I could use from a bag with my parabolic reflector. The Fostex seems to have had a lot of good things said about it and at £140, it seemed a reasonable price to get me a good low noise recorder that would open up using XLR mics.
I am obviously still aware of arguments of why I could/should have gone a different route, but I feel more relaxed now that the deed has been done and I can move on to investing in microphones and learning how to use them. I think that once I have some good microphones, and know better what I want/need I will feel happier in spending money on a more expensive recorder.
But, I'm very glad I asked my question as it was the comments here that made me rethink what it was I really needed, and made me consider things I hadn't thought about.
Cheers,
Graham