First, this is an outrigger, not a proa.
      Second, this will be complicated to build, as there are nearly two boats worth
      of parts  here: steering linkage, aka folding, very narrow port shroud angle... But
      quite beachable, little heeling or rolling at anchor, no weather helm, available beach cat
      rigs, deck tent covering as much as 7x7', and good average speed.  And oh, the
      pleasure of lounging on a trampoline on a sunny day as the water ripples below you 
      so much nicer than a hard cockpit seat!
      Construction is plain, old, chined ply, taped or conventional, 1/4"
      throughout (ama could be less). Glassing might not be needed if stored under shelter. Akas
      hinge forward on I" dia. aluminum tube pins to reduce beam for trailering, and are
      held extended by pins and a stay lead aft to a tumbuckle. They can be "I" or box
      section, about 5" square inboard and tapering an inch outboard.  Ama can be
      bulkheaded, used for stowage, water ballasted, maybe a big built-in icebox?
      Accomodation for two will be primarily in a tent on deck made of three pvc pipe
      arehes.  The aft cabin (coffin?) might have a canvas berth, but I've tried such an
      arrangement and it's best for stowing things and a porta-potty. My preference would be to
      avoid the "2+2" effect of such a cabin, and go with a flat deck to save some
      time, weight, and improve performance