Hi All,
Here is what i finally did.
Firstly i chose to mount the servos in the middle of each wing, ( just because i wanted to test my skills )
For this,in the middle bay on each wing panel, i reinforced two ribs with 1/16" birch ply, from spar to the middle of the rib.
Before gluing i had cut notches for 1/4" balsa sticks. i glued this all, and put 2 balsa sticks in the notches .
Finally i made a mounting plate of the 1/16 ply and cut a hole for the servo and glued this to the balsa sticks and the ribs.
Seemd to be a very strong setup, but.....
Now i am concerned that i might have made this too heavy, unnecessarily. I have also reinforced the landing gear ribs with 1/16 ply from spar to trailing edges.

Do you think the weight can be a problem ?
Thanks for your suggestions
Gaurav