Wrb detail options for zone 6 – GreenBuildingAdvisor

I am currently self building a house in zone 6 NW Montana and I’m in the stages of trying to figure out the best wall assembly that is within my budget. I have 2×6 16” walls and plan to do fiberglass insulation with vertical classic ribbed metal siding. My question is what is my best option for wrb and rain screen. My budget limits me to not being able to use exterior Insulation so I know I will get some condensation built up on the walls from the metal siding. Hydrogap SA seems rather expensive so just wondering what budget friendly options there are out there? Thank you.