Bear in mind it is best for security to have a cross cut shredder which cuts the strips in to about 2" long lengths. Try the normal places; Currys, Comet and Staples.
If its the same one as I got its dead on for smaller amounts of paper. Works quickly and it's electric. So long as you dont stuff it will 10 pages at a time (stick to about 3), it does the job!
If anyone is interested, I got one in Woolworths yesterday, they had a half price offer on a cross cut shredder - �14.99 instead of �29.99 and it works brilliantly. Thanks all !