My sig is my first build. I had to reseat the CPU and Heatsink a couple times but otherwise it went pretty much flawlessly without any trouble. You'll be fine doing the building, though watching a few youtube vids ahead of time can't hurt.
I didn't see which GPU you ended up with but my 570 runs BFBC2, for example, beautifully @ 1080 if that was your choice.
Also, I have that sidewinder x4. It's nice but if I could do it over I may have gone with a Razer Lycosa so that the blue keyboard would have matched my Case LED's.
Good Luck with the build!