Tiny house structural design

The building is 1 story an will have a vaulted ceiling. I also plan to build the building on skids so that it can be moved however id like an engineered design on how I can put the building on a permanent foundation. It is a 12x23'8" building with 10' walls in the front 12'x16'4" with a 2/12 roof pitch with a ridge beam that will remain at the same height through out the whole building and 8' walls in the remaining 12'x7'x4". I would like to know the materials i need for the the ridge beam and how to support it from the floor to the roof. Also I would like to know how I can put the building on a permanent foundation with or without the skids.