NE Sta-Set
I like New England Sta-Set for sheets. I use 7/16" on my H37C, probably 3/8" on your H30. But there are many places on the Web where you will find recommended sheet diameter for your size of boat and sails. My mainsheet is a nice red. The jib sheets are flecked, red for port and green for starboard. Rigging-Only has some of the best prices, see Related Link.