The amount of ram depends on the applications and workflow/media. Will you be working much in AE or with 4K+ media? All in all the build looks solid. The Asus boards have the Thunderbolt card option so you may want to consider those.
I am going to be working with 1080 x 1920 footage, not 4K. I'll only use After Effects occasionally, but I will use it.
Similarly, I've looked up the capabilities of Thunderbolt, but I'm not sure where I would be able to utilize that with the Adobe applications. (Basically, I'm not sure how it would be advantageous over SATA III)
Also, I'm still unsure about how cooling would go if I were to overclock this CPU.
32GB of ram should be fine then. AE uses the most ram versus the other Adobe applications. If you plan to use AE with Premiere open then you may want to consider 64GB. Thunderbolt is simply a bus connection for peripherals. It's not in place of those controllers such as Sata 3. External HDD's that are Thunderbolt still have sata controllers. The different is simply the bandwidth available ie performance that can be utilized versus other bus connections such as USB3. Then there is the chain capability. A single HDD on Thunderbolt will perform the same as it would internal. It would perform the same for the most part on USB3 other than higher latency. However a 4 drive raid or an SSD drive which can provide far more bandwidth ie MB/s than USB3 would be better on Thunderbolt. There are also I/O devices for thunderbolt. That would be the reason for it.
I've been pretty torn with the 64GB of RAM; it is a lot more money, but I'm not sure how much difference in performance could be expected with upgrading from 32 to 64. I suppose that I could always change what SSDs I'm using to save money, but I still don't know what kind of performance difference could be expected merely from 32GB to 64GB DDR4 RAM.
.....unless you are using After Effects HEAVILY, 32GB should be fine. Your proposed drive setup should work just fine with 1080p material. You should not have to go beyond what you have proposed unless you plan on editing much more difficult codecs in the near future.... checkout J. E. Shorts comments made here on this forum concerning someone's questions concerning editing 4K.
You MAY want to add a very large, and very fast Seagate enterprise level 7200rpm HDD as your backup drive and to archive with. The reviews on the 4 and 6 TB enterprise level drives are amazing....the 6GB drive topping 200MB/sec. transfer rate !! Your 1TB internal "D" drive will fill up fast !!...you will need to offload things off it.
Your CPU, GPU, and memory will be very powerful.....in the future....if needed...you can always increase the speed of your storage to handle multiple video tracks of more difficult codecs. You could use the M.2 slot to have a PCI SSD for the OS, Programs, and pagefile...all running over 1 GB per second....instead of the 550 MB/sec SATA III limit imposed by the interface. Then, you can RAID 0 several SSDs right on the MOBO for everything else !!!
However, Asus, and others, offer even MORE high speed storage connection options.....direct PCI storage......thunderbolt add-on card....AND the "SATA Express" connections of 10Gb per second.
As the Haswell E 8 core chip ramps up its power draw and TEMPERATURE under heavy load, while overclocking at 4.3 to 4.5 Ghz.....you MAY want to use the water cooling. The CPU draws over 300 watts alone under heavy load while overclocked !!....so, make sure your power supply is reliable, with plenty of power to spare with everything else running.
I see. I currently have a 2TB External HDD that connects ONLY via a USB 2.0 connection. I was thinking about using that as a backup, but I know it would take a while to transfer. It's also only 5400 RPM. While you were saying how good the transfer rate of that HDD was, since it's a backup, does the transfer speed really make too much of a difference?
Also, I will regularly offload the exports once they finish. I'll never keep those on the SSD. I'll regularly clean out the preview files and media cache as well, but I do have an extensive library of media that I regularly access and would prefer to keep on the 1TB SSD. At the current moment, it's approximately 150GB worth. Considering this, I think that this should be fine. However, I need some aspects to consider.
I used to use Premiere Elements 11. I never realized what the media cache was exactly. I looked for it but didn't find it until just last night... only to realize that I had 327GB of Media Cache files that had built up over two years of video editing...
However, considering that I will now clean that out on a regular basis, for just a few projects, I'm not sure how large I can expect the media cache to become at any given time. (Let's say, at the most, I have ten separate projects that aren't finished, 1080p video).
Basically, I'm still not sure what I should allocate to each of the two SSDs, mainly because I don't know how large I should expect each file size to become. My boot drive is certainly going to be 256GB, but I'm not sure what all I should keep on it and what else I should put on the 1TB SSD.