There are many types of epoxy out there. Our personal favourite is System 3 out of Washington state. They make a whole range of products. When we added 5 feet in the middle of our boat in 2013 we used only Silver Tip laminating epoxy. It is great stuff, easy to mix with its 2 to 1 ratio. We used plastic 1 cup and 1/2 cup measuring cups from the local Dollar store for most of our batches. Carllie was the prime mixer. It also very thin (not quite like GRP resin) but it evens wets out biaxial and mat really well. Gets new sticky residue (blushing) when drying in moist and cool conditions. They also make a product called Quick Fair which is a 2 part premixed filler for final fairing. It is easy to mix and gives a consistent thickness and dries at 70F in 3 hours so you can start sanding.