Some where there is a page that lists the measurements of lots of different filters...A member who is not sto active any more wrote it up, but I can't find it.
However, I think there are a few options, depending on what size tank you have. The AquaClears 200 would work, but only for a tank smaller than about 20 gallons. Best bet--grab a tape measure, or go peruse through the LFS.