Thank you all very much indeed for your really helpful advice.
May I ask some supplementary qs:
I know that some trains go to Waterloo and that w'd be preferable to get to Bank in the City but I can't find a way to stipulate that when researching the fares. Is it according to the train operator?
The APs I found suggested I could do the whole thing for approx ^50 pd where I allowed approx ^10 for mileage, parking + tube across London (from Paddington). Am I wrong on that?
How much is a weekly/monthly season ticket please?
I've calculated 2.5 hrs door to door allowing for a short drive from home + .5 from Paddington on tube. Does that seem too ambitious to you?
My work hours are 10-6 (with some flexibility) but I don't think that helps in any way to off-peakness?
If you guys were contemplating such a relocation and didn't have any preference except to live in a lovely part of the country which station would you choose to be near?
Thanks so much for sharing your local knowledge