Well i finally did it, my wing is complete using only 2 sirfaces and a birail. Took a long time, and i have the rest of the plane to make still, but oh well.

i did as i said before, used profile curves that i extruded alone the length of the wing, alone other profile curve paths. this gave me the 2 surfaces for the top and bottom of the wing that i projected a curve onto, crucially a degree 3 curve i think (this gave me one trim edge for the top and bottom surfaces).
i then snapped curves to the inner front and rear corners of the surfaces and projected tangency, to connect top and bottom and provide the profile for the leadind and trailing edges of the wing.
Then i ran a birail round the wing. Its just like i said in my previous posts but i kept the curves simple to give me continuous trim edges.

Im rambling i know but i hope this helps someone a little, thanks for all the advice too.

B