If its mostly wood, it also depends on if you will rip/size your own stock or
if you will buy it s4s to size. Depends on the type of wood you're using, and
your budget. If you're planning on all-spruce, you can usually get it in the
size you want from AS&S or Wick's. If its something else, then you'll need a
medium-quality table saw.

In my case, I bought my spruce s4s, but more than 1/2 of my airframe was made
of white ash. I bought my ash lumber s2s and ripped it to size on the
second-cheapest Delta talbe saw I could buy at Lowe's. (I did use a Freud
60-tooth blade.) For sections over 3/4" sq. this worked fine. But my rib
stock (single-piece, batton-type ribs) was 1/4" x 5/16". This presented a
serious safety problem because my talbe saw does not have the option of using a
zero-clearance shoe. The stock kept wanting to slip between the blade and
table top. Not good.

Other than that, the first tool I would buy is a good shop vac. Following
closely would be a 10" drill press, a good chop saw, and perhaps a benchtop
belt/disk sander.

Hope that helps a little,
Harry Frey
Wright 1902 glider (hull #7)
Wright 1899 kite
Wright 1878 "Bat"