Can anyone recommend a wedge pillow that I can buy in the UK? I've looked at several on the internet, and don't want to spend a fortune if it's not going to work for me. Some of them seem to drop away quite sharply at the thin end of the wedge (maybe an inch or two) and I worry that might give me a problem as I do have low back pain issues. I'd prefer one that tapers away gradually. I'd be grateful if anybody could give me advice on their experiences on these.