iPad mini Any iPad mini stock in London?

Hello everyone, I'm from Brazil and I'll be in London in 2 or 3 weeks.

I wanted to buy there an iPad Mini 16 Gb WiFi. Do you know if they have stock at an Apple Store to buy it directly there, for example in Covent Garden or Regent Street? If not, should I try in places like John Lewis or PC World?

Thanks a lot.

Awesome, Fireball! Thanks for your help! ^^