This is intended as a modification to the list of hardware I put together here:
www.ixsystems.com
Be aware, this is a totally different system board with a totally different processor socket than the 32GB build.
Everything else can stay the same and the function doesn't change, but you change the system board, CPU and CPU cooler as well as the RAM from what they were to this:
This board uses Intel C602 chipset and can accommodate up to 512GB of RAM, I did a couple builds with these:
System Board: Supermicro X9SRL-F Motherboard Socket Socket LGA2011 System Board BIOS Updated
Price: US $174.99
CPU Mark score of 13146, should almost be good for 4K movies in Plex, works for me:
support.plex.tv
CPU: Intel Xeon E5-2650V2 8-Core Socket LGA2011 CPU Sever Processor SR1A8 2.60GHz
Price: US $60
CPU cooler needs to be a narrow ILM model like this (the one I use) but Noctua makes one also, it is flexible:
Dynatron R27 3U CPU Cooler Fan for Intel Socket Narrow 2011 Intel Xeon Series
Price: US $34.90
The system board and processor above are compatible with Registered (RDIMM) memory.
RAM: 64GB (4 x 16GB) PC3-12800R DDR3 1600 ECC Reg Server Memory RAM RDIMM Upgrade
Price: US $113.95 - for 64 GB
About $380 for this upgrade to the previous build list...
You can buy newer hardware, but the gains between the hardware revision listed and the next generation after it are minor, while the cost increases significantly. If you go a generation newer than that, the cost becomes so significant that most home-game users will be deterred by it.
Specific build components list - up to 32GB RAM
Mar 3, 2019: I put this together because I was directly asked for it (or something very similar) on several occasions. While this may not be perfect for you, I put three builds together using same model hardware and they have worked for my...

Be aware, this is a totally different system board with a totally different processor socket than the 32GB build.
Everything else can stay the same and the function doesn't change, but you change the system board, CPU and CPU cooler as well as the RAM from what they were to this:
This board uses Intel C602 chipset and can accommodate up to 512GB of RAM, I did a couple builds with these:
System Board: Supermicro X9SRL-F Motherboard Socket Socket LGA2011 System Board BIOS Updated

Supermicro X9SRL-F X9SRL-F-ME008 LGA2011 System Board Motherboard | eBay
Item Specifics: <br /> <br />Brand: Cisco <br />PN: X9SRL-F-ME008 <br /> <br />I/O Shield Included: No.
www.ebay.com
CPU Mark score of 13146, should almost be good for 4K movies in Plex, works for me:

What kind of CPU do I need for my Server?
This article is primarily aimed toward Windows, Mac, or Linux users who plan to run Plex Media Server on a...
CPU: Intel Xeon E5-2650V2 8-Core Socket LGA2011 CPU Sever Processor SR1A8 2.60GHz

SR1A8 Intel E5-2650 v2 2.6GHz Eight Core (CM8063501375101) Processor | eBay
Processor number E5-2650 V2. L2 cache size (MB) 2. Number of cores 8. Socket type Socket 2011 (LGA2011).
www.ebay.com
CPU cooler needs to be a narrow ILM model like this (the one I use) but Noctua makes one also, it is flexible:
Dynatron R27 3U CPU Cooler Fan for Intel Socket Narrow 2011 Intel Xeon Series

Dynatron R27 3U CPU Cooler Fan for Intel Socket Narrow 2011 Intel Xeon Series 855700013276 | eBay
Solution: 3U & Up, Workstation & Tower Desktop Solution. CPU Socket: 2011 (Narrow Type, 56 x 94mm mounting pitch). At Duty Cycle 20%: 1000 RPM. At Duty Cycle 50%: 2000 RPM. At Duty Cycle 100%: 3800 RPM.
www.ebay.com
The system board and processor above are compatible with Registered (RDIMM) memory.
RAM: 64GB (4 x 16GB) PC3-12800R DDR3 1600 ECC Reg Server Memory RAM RDIMM Upgrade

64GB (4 x 16GB) PC3-12800R DDR3 1600 ECC Reg Server Memory RAM RDIMM Upgrade | eBay
Find many great new & used options and get the best deals for 64GB (4 x 16GB) PC3-12800R DDR3 1600 ECC Reg Server Memory RAM RDIMM Upgrade at the best online prices at eBay! Free shipping for many products!
www.ebay.com
About $380 for this upgrade to the previous build list...
You can buy newer hardware, but the gains between the hardware revision listed and the next generation after it are minor, while the cost increases significantly. If you go a generation newer than that, the cost becomes so significant that most home-game users will be deterred by it.