How easy is it for you to get to London? Lots of Health Food shops where you can get all manner of stuff. Holland & Barratt sell soy flour. Must admit I'm looking (not very hard yet) for the protein powder. I got myself a packet of wheatgerm (the highest protein bit of the grain) and considering the minute amounts I'm using it will last me a while.

I KNOW protein whey is available in the UK. I've seen it and eaten it too at residential workshops.

Good Luck in your search.