Belfast's hull was primed with Jotun Penguard HB 2 part epoxy primer, and the same was used internally for the bilges.
If you are going to use part cans, the weight of each component you need is given at https://www.smlmarinepaints.co.uk/uploads/files/library/files/2 pack weights 0314.pdf. Get yourself a cheap set of digital kitchen scales to weigh out the 2 components - a fiver from Asda when I bought mine.
Since your boat is already out of the water you would get the best out of a 2 pack epoxy paint system if you had the hull shot blasted first. It will cost, but it will be a better job and will save you days or weeks of running around with an angle grinder and wire brush.