Hire contractor or hire architect for exterior insulation details? – GreenBuildingAdvisor

Hello, all. Any recommendations on how to plan and hire out exterior insulation installation as part of a whole house re-siding project? Hire an architect to draft details, hire design-build? Any other options?

I live in southern Maine and our home is from 1880’s.  As we’ve tackled minor remodels, we’ve added interior insulation as the budget has allowed. Embarrassingly, it’s a mish mash of blown-in, some rock wool batts, some rigid foam. 

We plan on re-siding the house this year and I’d like to add exterior insulation (rockwool comfortboard or similar) but am concerned about getting the details right (windows, rain screen, bug screen, flashing, etc.)

How would you folks go about it? Hire an architect to draft design then get quotes? Find experienced contractor that specializes in this type of work? Any and all guidance is greatly appreciated!