Assuming its the original hose, you'll need to convert the hose/regulator to the newer style that will fit any standard tank. Seems to me I've seen them for about $20-$30. Your local hardware store or big box should have them. Take the old one off and inspect it prior to shopping to insure you get the proper fitting.
If you don't want to use a large tank, you can buy 5lb tanks, but they're kind of pricey, IMO.