The Z170 motherboards supports 6th-gen Intel CPUs out-of-the-box. Since you selected a 7th-gen CPU (i7-7700K), you would need a BIOS update for that i7-7700K to work with the Z170 board. This means plugging in a Skylake CPU first to be able to boot and update the BIOS. To eliminate this hassle and issues, just get a Z270 motherboard which supports 7th-gen out-of-the-box. Note that 7th-gen CPUs require Windows 10 operating system. Alternatively, if you really like the Z170 motherboard, just get a 6th-gen Intel CPU (such as the i7-6700K), which works with Windows 10 or lower versions.
If this build is purely for gaming, you can save some money if you opt for an i5 instead. Though some games may benefit from the 4-core/8-thread the i7 offers (but not most games). The i7 is, more often, geared towards gaming AND multi-tasking/editing work. But if your budget permits, by all means go with the i7.
Based on your list, it tells us that you will plan to overclock that CPU. The CPU Cooler you got is not the best out there (but best in affordability). Alternatively, you can look at the Cryorig H7 or H5 or the be quiet! Dark Rock 3 which are all affordable and has better cooling performance than the Hyper 212 Evo.
If you don't plan on overclocking, then, getting a locked CPU (the non-"K" versions) will save you some money. Pair these non-"K" CPUs with a B250 motherboard (for 7th-gen CPUs) or H110/B150 motherboard (for 6th-gen CPUs) to further save costs if not overclocking. These locked CPUs have a Stock Intel CPU Cooler included, which will suffice for the lower heat/TDP generated. Getting an aftermarket CPU cooler is optional for locked CPUs.
The GTX 1070 GPU is best if you will be gaming on a 1440p/60Hz monitor or 1080p/120Hz++ monitor (preferably G-Sync monitor). If you are only looking at gaming on 1080p/60Hz, then your original pick (the GTX 1060) will suffice, as well as an RX 480.
Depending on your storage requirements (esp. for games you wish to install), you might want to add a 1TB HDD to pair with that good-quality Samsung 850 EVO 250GB you picked.
The 16GB RAM is good, but if budget is limited, an 8GB is considered minimum. Some games benefit from 16GB RAM, most games are good enough with 8GB. Main advantage of 16GB RAM is geared toward multi-tasking/editing works. If your budget permits for a 16GB RAM, then get it.
The 650W PSU is slightly an overkill for the system you will be running. The EVGA NEX series is also not the best out there. You can save more money by getting an ample-wattage PSU that is more than enough for your system. Based on your list, a 550W will suffice (with headroom already for future upgrades). If you like EVGA PSUs, look at the SuperNOVA G3 550W (7-year warranty). Another option is the Seasonic G-550 (5-year warranty, hybrid-modular cable). If you have a large budget, you can get the Corsair RM550x (10-year warranty, fully-modular). If you want to save a lot, you can get the Seasonic M12II-520 EVO (5-year warranty, fully-modular).