I am also planning the build so I cant say things for sure but I think it is fine to put SFX-L and GTX 970 together. Although I personally would wait for Corsair SFX PSU.
For the motherboard, I decided to go for Asrock Fatal1ty Z170 because of the oc ability and M2 slot.
For the motherboard, I decided to go for Asrock Fatal1ty Z170 because of the oc ability and M2 slot.