I won't have a tonne of cash to spend on the project. I was thinking probably £3k a switch.

Our colleagues in the newspapers use HP Procurves in pretty much the same configuration that I'm after. Sadly we're the poor cousin when it comes to getting money spent on us. I'd be inclined to use same ones, but they have had their fair share of issues with them.

EDIT: The only other thing I should really consider is PoE.