A Farmer's Market would be great in Sydenham. There are some lessons to be learnt from markets within the Brockley New Cross area:
There is a small, overpriced French farmer's market on Telegraph Hill in New Cross which lacks any atmosphere. Needless to say this isn't great, despite being run in a lovely little park. I think it's failure is due to the fact it's on once a month and has a very small selection of stalls.
The Brockley Market is fantastic. It has a great selection of stall (some of which I think went to FH last Sunday),the branding, twitter account and website
http://www.brockleymarket.com/ is a little ott, but it all works well and regularly pulls in the punters. It takes place in Lewisham College car park, which is not far from a main road (A2) - but once packed it looks great.
The High St plans include 3 spaces for market stalls:
http://www.lewisham.gov.uk/SiteCollecti ... posals.pdf
They note that there is 'space' for market stalls, so it doesn't sound like there are any plans. And it will be a real shame if they don't fill these spaces. Surely it makes a lot of sense to try and work them?