Bizman's advice is perfect - as for builders, IMO if a reputable local place with good prices/matching, and especially if they have a good rep with RMA/warranty, is a good way to go. NCIX as stated is one such place, when I was on the West coast I used them frequently in Canada, Memory Express as well - both charge around 50$ USD to assemble your PC, test it for a day or two, and then ship it or have it picked up. I know many recommend building yourself, but that 50$ is money well spent if you are having the parts/PC shipped, as they will instantly pick up any DOA parts and replace them before you even know about it, where as in my case, to use my place (Mem Express) since I've moved away from their home base is a 500 mile trip/weeks worth of shipping time. That's worth 50$ to me to know I won't have one of the dozen or so parts not function right out of the box, plus I know their builder(s), and they always do a good job with cable management and such.
Digital Storm, Puget Sound, places like that are great too, price things out with them as well depending on what you want.
As said, Skylake i5 with a 1070 should do you well for a long time for most games at high detail/res settings. The 1070 will apparently do everything the current Titan can and then some, and if you aren't doing vid editing or other CPU intensive non-gamer activities frequently, you can save $ going from i7 to i5 without noticing much in the way of FPS drops. If VR is in your future, I've read several places that there is a BIT of a performance gain between the 6600k to 6700k, but I suggest doing your own research into that if its a concern.
I'm running 2 1080 on an 850 PSU in one system (1300 in another) until I get my new PSU in the mail, and it's powering them both fine along with an SSD and 2 other drives, so I'm sure a 750 will more than suffice for a single 1070 and everything else you want.
