Hi OF! I've had a bit of a look and the following sites will give you a fair idea what you're looking for

Sim Only Deals

MoneySupermarket

Other sites to check are the supermarket sites, as you can get SIM-only deals there too.

Tesco or Asda amogst others, though these two are the biggest and hence (probably) cheapest.

The other option is simply to buy a cheap PAYG phone when you get here - you can get them for under £30, and that way it doesn't even matter that much if you lose it!!

Anyway, I'm sure you'll both have a terrific time here - will you be up in Scotland at any point? (watch out for the midges, if so!!)

DM

__________________
The selfish, they're all standing in line
Faithing and hoping to buy themselves time
Me, I figure as each breath goes by
I only own my mind