You can get two types of chopped strand matt. Styrene bound, suitable for use with polyester and vinylester resins, and powder bound, which can be used with any type of resin including epoxy.
Powder bound matt is more expensive than styene bound, so unless you're using epoxy resin, there is no advantage. Cloth laminates give a lighter more flexible laminate than CSM, but not as rigid. Therefore laminators sometimes sandwich a layer or two of CSM in with cloth to stiffen the composite structure.
I would use epoxy resin for your boat, it's much nicer to use than polyester, and the extra cost is not huge for one offs like this. I highly recommend Reactive Resins for epoxy resin, a Cornish based supplier. Really nice resin, and very good prices. For other types of resin I have used CFS, who are also excellent.