Tooling is the mould you take from a master to make a hull from. I would say double the thickness of the finished hull is a minimum, some would say three to five times thicker, especially if you're going to make lots of hulls, but for one or two you can get away with a thinner tool.
Cloth is much more expensive than csm, and offers little benefit for model boat hulls save for where weight is a consideration (e.g. fast electrics yachts etc.), and also is more prone to delamination with polyester resins. It's much more commonly used with epoxy resin, which bonds with greater tenacity, and also has higher mechanical properties.
If you want a smooth finish to your laminate, just add a final layer of glass tissue over the csm before consolidation.