RE: What to buy
You won't want to use only epoxy for the build. Wood glue dries much lighter weight and leaves very strong joints. You will need thin CA for hinges unless you buy plastic pinned or Robart hinges. You can use epoxy for these kinds of hinges.
A plane build completely with epoxy will weigh significantly more than one built from a variety of adhesives, assuming you use the right glue for each job.