5x5:
I used HS 425's all around on my 1/4 scale clipped Cub. Worked
fine for a Sunday poke around plane. If your planning to crank
around non scale then I would go 605's . My Pica Aeronca Sedan
has 425's for the back-end but a HS 705 for the ailerons because
it has the one servo for both.

Randy