Kinder Industries of Bristol, Ri makes great covers. The owner is an A-cat sailor and has done many cat covers. He told me they were using my 6.0 to make a template off of, not sure if they have done it yet but i'm sure they would.
Their website is www.kinder-industries.com
As far as storage, if the sand is soft and fine (no rocks) I would just leave it on the sand, if there are rocks or anything that will scratch the hull I would get any kind of foam (pool noodles work great) to protect the stern and leave the cat trax (with cradles) a few feet back from the bow. This way the boat will be supported in the front by the cat trax and in the back by foam, just enough to keep the hull off the sand. If your cat trax don't have cradles, which they should, just put more foam under the front.
-Todd
N6.0 #308