Depends to some extent on your finishing method and the size of the plane (in this case, say a 650 square inch wing). Generally, if you are covering with silkspan (GM or SGM) it will take about a quart of clear butyrate lacquer, possibly a pint of filler (I use clear and talc with a bit of gray paint in it), a pint+ of base color (depends on the color - more transparent colors take more paint) and however much trim you need. If stripes, probably not much. About 3 pints of thinner and I use some retarder in humid conditions to allow moisture to escape.

I generally buy clear, non-taunting Randolph's or Certified in gallon cans along with thinner in gallon cans.