SW is the most important for me also.
I"m 5'11" and a porky 158 now, but usually play at around 145.
No excess of muscle, I like the SW of 310 on my 500's, can handle the 320 SW of McroGOS, but get sore wrists and shoulder's from 337-350 SW's.
My LMRadMids are fine at 325, but the stiff top of the head kills my arm.
Since your're stronger, you should be fine with about a 340 SW, especially since your game is more baseline oriented and also more rally oriented.