Im am about to start my pep armor. But am wondering how much resin i should buy. I was planning on buying it in gallons. I am 5ft tall. I want a 2 layers on the out side and 1 on the inside. So how many should i purchase? Would that be strong enugh? I really dont want to spend to much money($150 bucks to spend) so is that enugh since i have every thing except resin?