So, I've been planning this new server build for a while, and have been slowly accumulating the components as they go on sale. Some items I picked up at a premium because they were being discontinued, or because they were finally back in stock and didn't want to risk not being able to get them. Goals for the server were to EOL my Windows Home Server that's been chugging along nicely for a decade, but replicate all the functionality. Because I only recently decided on the NAS software (OMV) after trying everything in virtualboxes, I ended up with some overkill (mainly the OS drive), and there's some overkill as well because I want to provide huge expansion capabilities/live transcoding of multiple 1080p streams on Plex.
Components I already have on hand:
Case: Lian Li PC-D600. It's a monster, full ATX with two compartments. One for all the drives, one for the motherboard side. My wife dictates that it be quiet, so I thought this might help. Plus, it looks cool.
Motherboard: ASRock Z270 Taichi. Mainly selected for the 10 SATA 6gb/s ports, and that I can put one NVME (it has three slots) in without disabling any of the SATA ports.
CPU: Core i5-7500 - after lots of research, price/performance was the best for transcoding what I wanted.
Graphics Card: AMD RX460. OEM that I picked up for $45. Only for setup, so that's why I tried to find the cheapest I could since there was no integrated graphics on my CPU.
Memory: Micron Ballistix DDR4-2666 2x8GB. A little faster than what I originally planned, but it was on sale for cheaper at Micro Center, so why not.
NVME Drive: MyDigitalSSD BPX 240GB. A little large, but again - had no idea what I was planning on for OS. Should have plenty of space to install all the plugins and their supporting libs that I plan on using.
SATA Controllers: 2xIOCREST SATA 6gb/s PCIe cards. 4 ports per card. Selected these because there's support for Linux kernel 2.6.x and above. Should have support for 18 total drives. 15 will be storage, 2-3 parity drives when maxed out.
CPU Cooler: Deepcool Captain 240EX White.
Case Fan (HD side): 3 x Arctic P14.
Power Supply: EVGA Supernova 1000G+, was planning on 850 Watts based on my calculations - but this was on EVGA's Midweek Madness for $70.
SATA Cables: 4 x Micro Connectors sleeved SATA cables in white
Backplane Fans: Noctua NF-90 x 3. Swap out the stock fans that come with the backplanes to something quieter and more efficient.
SATA Power splitters: Not enough SATA plugs on the PS, so I need MOAR POWER.
Components still to buy:
SATA Backplane: 3 x ICY Dock Fatcage. Selected because it was 5 drives in 3 bays, and I could remove and replace the fans.
SATA Cables: 14 x Micro Connectors sleeved SATA cables in white
PS Cables: Individually sleeved in white, probably going to go with EVGA's vice cablemod (price)
Hard Drives: Was going to go with WD Gold, but found Seagate Enterprise 4TB, 7200rpm, 128MB Cache for $25 cheaper per drive. Starting with 5 (3 data, two parity) going to add/upgrade from there.
MB Side fans: Might go with RGB, might not. Planning on 2 140mm & 1 120mm.
Don't ask me how much I've spent. I don't know. And I don't want to know! 
