Mike,
I've just had a 'google' and couldn't find any at all for December - anywhere in the UK.
I know you're a Macam, but still I thought I'd try to help; even if I am an arch enemy; a Geordie.
But, Mike; if you read each WFP back posts (I know this may take some time) on this forum, then start re-searching each website that supplies them; I think this may give you an alternative option to a trade show.
Texas Girl, funnily enough from Texas says that because the majority of her work is residential and that they have 'insect' screens to contend with and that WFPs would not be practical.
As an overview to WFP; I find Matt's DIY Water Fed Pole site excellent. It explains what you need and why. You can find it here:
http://d.co.uk/I hope I've been of some assistance.
Regards,
Tosh.