1) The E3-1231 V3 is not the best choice, nor is the i7-4790.
The E3-1231 V3 costs slightly more than an i5-4690K. While it is hyper threaded it ends up slightly slower for gaming where a bottleneck even exists due to the i5-4690K's higher frequency (4.2GHz on simple XMP profile).
That's ignoring any further overclock which is easily done though I'd just stay at 4.2GHz (or possibly 4.3GHz) with the XMP or slight-overclock method (see motherboard manual).
2) DDR3 memory:
16GB isn't needed yet, but if you want to future proof that's fine. You won't see a noticeable benefit beyond 1866MHz CAS9, plus I'd get whatever is cheapest of the same model 4x4GB or 2x8GB.
THIS is slightly cheaper, possibly more stable, and will perform in the real-world as good as 2400/C10 memory:
http://www.pccomponentes.com/g_skill_ripjawsz_ddr3_2133_pc3_17000_16gb_4x4gb_cl9.html
3) Motherboard:
If you haven't yet bought a board I suggest the Asus Z97-A for the same cost instead which is likely higher build quality:
http://www.alternate.es/ASUS/Z97-A/html/product/1138758?tk=7&lk=8726