For the ASUS z170 WS and Samsung 950 pro 512 gb M2 SSD, assumint I'm using the top PCIE slot for the single VGA card, is there a preferred slot to use for the M2 SSD with my setup? The M2 drive speed will be the highest priority, but I'm also trying to maximize the number of SATA ports available for media storage.

I just ordered:

ASUS Z170 WS motherboard
i7-6700k cpu
Corsair 115i AIO cooler
G.Skill TridentZ 2x8gb DDR4 3200 14-14-14-34
Samsung 950 Pro 512gb M2 SSD.

I haven't chosen a graphics card yet, but it will likely be a single ASUS GTX 970 Strix. Going into a Fractal XL R2 case. For a gaming and future proof HTPC computer.

Any feedback greatly appreciated. Thanks!