I've got a 31 inch one (79cm) from PetPlanet. It's quite small for him now he's nearly full-grown. But he barely goes in there any more.
I actually have a spare one (Heavy Duty) which I got for my parents house, which we don't need any more. If anyone needs one and is in the SW Herts/Bucks area and wants to pick it up I'll sell it - including vet bed and divider - it cost me £47 and it's been used about 8 or 10 times, so is practically new. Open to offers...