Quorn is a unique product...at least, I'm not aware of generic Quorn in the UK, although I believe it does exist.
I think Beanfeast is made from soya (but correct me if I'm wrong) but I find it has a texture more like TVP (which I suppose Soya is a type of).
Much cheaper than most Quorn, but I can't say I enjoy the *ahem* effects it has on me the following day ;-)