In most tests the U9S beats the D9L (It has an extra heatpipe) Orientation frankly I doubt makes a huge deal. Horizontal I believe is better for RAM compatibility.
The 1070 turbo is loud. Consider an aftermarket unit or a founders edition, I wouldn't really bother with any other blower styles that I've seen IMO.
If you CAN, the Noctua NH-C14 is still the preferred air cooler for this build. But the U9S should do the job well enough
Okay I just found a noctua c14 and I bought it. Just one question, which fans do you recommend do place on the side for fresh air? Maybe two Noctua NF-F12 120mm or what do you think?
Maybe I am wrong but to me this just seems like it would make more sense. You get fresh air intake at the right which feeds right into the heatsink and exhausts out the back. If you mount it vertically it doesn't seems like it would get as good an air supply. I would love to see someone mount one both ways and post comparison temps.
http://www.guru3d.com/articles_pages/noctua_nh_d9l_and_nh_u9s_cpu_cooler_review,1.html Good comparison here between the two.