I bought a set on eBay for about $10 that I am very happy with. I bought ones that fit into a 3/8" ratchet and are about 3" long. The end that goes into the ratchet is knurled, so it makes it easy to snug or loosen with your fingers when the bolts are loose.
I learned a tip from another 'bolter that I'll pass along. If you buy a set as described above and run into a frozen clutch head screw or bolt, use a hand impact driver to get it out. These are the impact drivers that you whack with a hammer. It was a great tip and it usually works. Much better than my old technique of cutting slot with a Dremel to fit a large flat screwdriver blade into the head.
Matt
