DDR4 for new build, o/clocking not reqd.

[pieman109]

I'm gonna be upgrading me pc (see below) shortly and while I've got my options sorted (depending on Zen, s/h market etc) I'm totally in the dark regarding the memory.
I'm gonna need some DDR4 but have no idea which brand, speed would suitable for me. I'm not interested in overclocking it, I'll do that on the cpu and gpu, so what are my options here?
I fancy the idea of buying a single 8gb stick to start with to keep costs down a bit then adding another 8gb shortly afterwards.
Any info/opinions greatly appreciated.

 

[pieman109]

Thanks for info guys, very useful. One thing that'll sway my decision is that Skylake 'frinstance doesn't support single channel ram apparently (would appreciate it if someone could confirm this) so its looking like 2 x 8gb of DDR4 of whatever I end up choosing.