I should have known it would be too much of a coincidence! I'll be running in Geneva, Switzerland.
I've been Vegan for a little over a year now and totally love it. It must be really difficult for you with those allergies but there's a lot of different grains out there so hopefully something for everyone! I eat a lot of brown rice, but there's also Quinqoa and keffe I guess.
At first I found going Vegan really hard - this is a meat and cheese eating culture for sure so it was a big change. However, I bought some really good cookery books (I must admit I don't really go in for the mostly raw thing in the thrive diet) and they completely opened up a new way of cooking for me and loads of new foods that I didn't even know existed before. Check out "vegan with avengence" and "christina cooks" for ideas!
Best of luck with your training - how's it going? What sort of training plan are you following?