When someone is in your position, I usually try and get the architectural drawings done first so that the client and others can see what the entire finished design will look like. Run that past everyone and make all the changes that come up (and some will come up) and then put the frame inside the shell of the house.
Modify the frame to fit the shell so that all windows and doors will open and not be effected by brace locations.
After the client approves the shell and the frame then send it out to engineering to be reviewed and update the frame from the engineer's input.
After the engineering is done you'll have everything needed to get bids for the frame materials and enclosing the design.
Good luck with your project.

Jim Rogers