I'm currently investigating possibilities in the
UK, so please do check
into it for me. What I'd need to know right off is what, if any, fees
would be required to rent the required space, and how much those fees are.
Would collaborating with one of the bigger ham radio rallies be practical?
(probably wouldn't be enough spare space at the obvious choice of
Donnington, tho' that location might be cost-effective standalone.)
In London the best bet is probably Excel ... but even that is likely to be
too much.
Best accessibility is going to be the midlands - somewhere like Loughboro'
is in range of London, York, and Manchester but less than optimum for train
travellers.
Andy