I use the gutter and LOVE it. I've been carving pumpkins since the middle 80's and just got one a couple of years ago. I sure wish I'd had it all along--would have saved my elbow and wrist from all that scooping/scraping wear-and-tear, plus it saves SO much time and allows me to get to the fun part of carving pumpkins (the actual carving!) much quicker. Amazon sells them and ships to the UK. http://www.amazon.com/Dakota-Products-P ... kin+gutter
A clay loop, as S.A.M. suggested, is excellent for shaving down the inner walls. For me, the pear shaped one works the best (the one pictured in the link S.A.M gave you). You have to be careful because it works so well, you can easily scrape too thin or even break through, as I have done a few times. I use this to thin down the walls after I use the gutter to do the major part of the work, but this will work just fine in place of a gutter.
Another very useful tool is a linoleum cutter with U and V shaped tips for shaving the outer skin if you do shaded pumpkins. You can find them in sets pretty cheaply. I use this "Speedball" http://www.dickblick.com/products/speed ... m-cutters/
. It's very handy as it comes with several different sizes of sharp-edged tips which store right in the handle. I have a few handles so that I don't have to stop and change tips. You could most likely find one like it in the UK, or maybe Dick Blick's will ship overseas. There are also miniature sculpting tools, called "ribbon tools" that are perfect for smoothing out the shaved areas of your carvings. They come in sets of various shapes. Here's a link to have a look. http://www.dickblick.com/products/mini- ... cking=true