I should have added a point 4) that government regulations require certain standards to be adhered to.
http://www.zdnet.co.u...conomy-bill-40057470/
The first place I'd suggest they call (if it's a tied pub) is the brewery, they might find that a lot of them have preferred providers for this sort of thing with discounted and/or subsidised rates available. (I think punch, green king and enterprise have preferred suppliers of the top of my head)
If it's a free house (or the brewery can't/won't help) then the cloud is probably the largest provider of public hotspots for this.
http://www.thecloud.net/