Here's a smaller one. It cuts up to 12" X 6".
http://www.ebay.com/itm/Provo-Craft-...item4843b0cc9e
This is the one that I have. It cuts a 12" square piece of paper and even a 12" X 24" piece of paper but you have to have a mat that size to do it and I don't have a mat that big. I really haven't had a need to cut anything that big but I do use it to cut things larger than the smaller one could cut.
http://www.ebay.com/itm/EXPRESSION-M...item43acaa0af9
If you look for a used one on e-bay you should be able to find one for a good price. Just remember that each cartridge costs $20-30 or more. That adds up pretty fast.