First question, how wide is a Halfpint pan? Second, what size evaporator do you hope to have "down the road"? I don't know what width a halfpint pan is, but lets say its two and a half feet wide, you would want to fashion the new pan to what a 2.5x8, or 10' rig would have for a syrup pan. Likewise for a 2 or 3 footer. My homemade 2.5 wide syrup pan has 4 compartments and has a floatbox on each side. Can the halfpint arch accept a pan that has float boxes on it? Is it a newer style arch (box-like), or is it the older steel barrel arch type? I'm thinking the newer style just has the pan setting on it and the barrel one the pan sets in it. The older style would need some modification, if I'm remembering correctly. I'm sure others here will share what they have for compartments, and you could always look on e-bay, craigslist, Bascoms, etc., and see what other pans close to what size you want have for compartments.

Steve