Hi there,
The only white bread with no soya that I have found are those baguettes that you need to bake in the oven yourself from Tesco. They come in a pack of 4 but my LO loves them.
Otherwise, we get her the Golden Wholemeal bread from Marks and Spencers (but it's not white), crumpets or some of the wraps, like Mission Deli. I think there are some pitta breads that are soy free but they vary so much from supermarket to supermarket that I can't remember the ones we got (we haven't bought them for ages).
And when we are in the mood, we use the breadmaker!