So first time posting but I work in IT for a living and I really enjoyed this a lot! It was quite amusing really! I am going to post what parts I think would would better for your build and go into detail why I think they are smarter buys then what you currently are using.
Heat Sink (URL)
first off I would like to point out that your 1U passive CPU cooling is for an LGA 1156 and NOT an 1155 ( the socket type for your CPU) This is why in the video you had to cut parts of the back plate off to make it fit onto your motherboard. You should get a different passive heat sink. I would Recommend this one. It is expensive because it is made almost entirely of copper. When you are dealing with passive heat sinks you shouldn't skimp on price and you should be getting the best.
This is the only major Change I would make to the build if you wanted to keep costs down and not replace more parts but that being said I do have a few more recommendations.
1U rackmount Chassis (URL)
The next thing I would consider buying is a new chassis to fit into your 1U server rack. This Case comes with pre-installed with a 200W Power supply and I know that a lot of people dislike that idea and I also have the feeling you liked the idea of having a Redundant power supply option on it. A redundant Power Supply I feel for this kind of build is not necessary. It will be a waste of space, excess heat and noise. My last point for recommending it is This case is not as Long as the one you currently have so it will use up less space!
Chassis Specs
Mother board (URL)
Last but not Least I would Recommend a Larger form factor for your Motherboard. I have server things I dislike about your motherboard pick and the big one is airflow. More fans will not make up for the lack of airflow over the passive Heat Sink. Yes I did notice that you got the smaller form factor to make up for that but the CPU will run a lot warmer that it needs to because the RAM is in the way. By using this Motherboard you have the Ram off to the side where it won't get in the way. The SATA ports are to the other side of the board for better cable management and Board near the CPU socket is generally devoid of any major obstructions compared to the MoBo you picked that is so compact that The heat sink was impossible to install correctly. Also this board comes with more features than the one you picked up and also for the same price!
Mobo Specs
Closing Thoughts
One thing to keep in mind is that the Motherboard and Case both came from the same company. This means the Motherboard is Optimized to for specific cases. I did not pick the best optimized case for this build and opted for a different case instead but the form factor remains the same regardless. In terms power you should be ok for the system but if you fear 200W is not enough I would consider upgrading to one of their other cases then.
Overall i really Enjoyed watching this video and I hope this info was helpful to you!
PS: If you need a systems admin let me know!
Edit:
If you decide that after all this You want a powerful switch with all the things a Systems admin would need then I would recommend the following Managed Switch.
TP-LINK TL-SG3210(URL)
why This Switch? well it is a very high quality Level 2 Managed Switch with enterprise style features without the enterprise style Price.
It supports QoS, has options to prevent Typical DoS attacks, has ACLs (access Control Lists) and will even allow you to setup your own VLAN.
And Finally the switch supports 802.1X authentication whitch is used in conjunction with a RADIUS server (as mentioned in the Comments).
I know a PFsense Router is a cool idea but this is ultimately what you need.
Edit2: This Switch can be rack mounted with Mounting rack ears so it will fit!
Malwarebytes is one of the best anti-malware solutions you can get. I also would recommend it! very good free edition.
