Flaps in the stock wing seem to make sense.
Check out this thread. http://www.rcgroups.com/forums/showthread.php?t=1688402
His wing is so nice compared to mine, but I have the same basic setup on my building bench now. 4 servos in wing. Fowler flaps setup for massive rotation if you want to use it.
I didn't weigh my wing before I started, but after adding the CF rod, 4 HS-55 servos and the wiring, the wing is under 7 ounces on my build.