The xbox one s controllers works with the original xbox one,which do not have any bluetooth integration... And you can also connect the original xbox one controllers,which do not feature bluetooth, to the xbox one s.....
Forgot to mention that I live in sweden and they don't sell them here... might be able to buy from amazon in the uk though. Not sure about shipping fees..
Both allow overclocking. Also if you want it cheaper you could change the 1700 to a 1600 (link 1)
I'd recommend build 2 if its purely for gaming and build 1 for other stuff like streaming video editing etc
On amazon: https://www.amazon.com/CableMod-300mm-Magnetic-Light-Strip/dp/B01GI60HVG/ref=redir_mobile_desktop?_encoding=UTF8&dpID=41L9Wmy4Y2L&dpPl=1&keywords=WideBeam Magnetic RGB&pi=AC_SX236_SY340_FMwebp_QL65&qid=1511780978&ref=plSrch&ref_=mp_s_a_1_3&sr=8-3