Took a kite building class from Ken Conrad a couple of years ago. The Buka Dako. Only learned about five or six things.
The classic proportion is 1.3 to 1.
Get the leading edge straight and square.
If you use round carbon fiber: Make a jig out of house hold items to hold bends in the rod. Set up so the ends of the rods lay flat. glue paper cards onto the ends of the rod. The results being when the rods are installed on the kite they will be aligned to the natural bend - the cards being a temporary indicator.
There is rectangular carbon fiber rod available. Check it out. I've seen two sizes.
Bow adjustments can be made by wrapping the bow line around a small amount of the leading edge spar that protrudes from the kite.
Line tensioners. There are a variety of them in - kiting in general.
Ken uses a real cool knot. Old school from japan. It grips or slips depending on what you want it to do.
Buka dako's pull like a mule. I'm talkin' 150 lbs. test line, gloves - all that stuff.
Ken Conrad runs Great Winds kite shop in Seattle WA. He's a true kite god and real nice guy. If you show up some time (bring money) maybe he'll show you the knot or give you some tips if he ain't too busy. He's usually a Ft. Wordon too.
While yer' at it take a lesson from Bruce, Dennis, Chuck or Brian. These guys have been working on Buka hybrids. Quite a bit different than the big old hairy Japanese kind a' kite.