I've had most spin production out of these setups:
Tier 1 FireWire 1.25 / Pro's Pro Red Devil 1.18
Mayami Big Spin 1.25 / Polyfibre Black Venom 1.15
Mayami Tour Hex 1.23 / WeissCannon Mosquito Bite 1.16
Yonex Poly Tour Spin 1.25 / MSV Co-Focus 18
I've tried soft strings as mains, but spin production was not as strong as from the stiffish strings.