Youtube has a lot of videos on the subject.Harmony may not run or work properly on other distributions. Google “Wacom tablet alternatives” then come back and do a search here and ask about compatibility. Just get the small size in either the Wacom or a competitor’s brand. If you can fit it in the budget a Wacom Intuos Pro is a pleasure to use. There are many models and brands of basic drawing tablets that are compatible.
A basic hard drive will get you by but an SSD for the operating system and additional applications for speed with a 2nd internal non-SSD drive for storage would be great. They key is to set it up properly and then to routinely open the software properly, (it is only a matter of checking boxes in Preferences and dragging the welcome screen from the main display to the secondary display before opening a project). Toon Boom does not officially support dual displays but it is possible and I have done it flawlessly running TB Animate Pro 3 and Harmony 12-15. A 32" would be great but two 24" displays would be better than one 32" display. You want an i7 processor and the basic GTX 1070 or 1080 graphics card. The “TI” and “K” would be wasted money with no performance gain in Harmony.
I suspect that is beyond your capabilities. You also do not need a “K” series processor unless you are going to overclock.
(this was when the GTX 970 was the latest so the GTX 1070 is current). I determined the sweet spot would be the NVIDIA 70 model. When I was in touch with TB Support as I planned out a system I was building I was informed that Harmony does not utilize the NVIDIA “TI” features. System 3 is 1299 dollars and includes the i7 processor and an NVIDIA 1070 Ti video card System 2 is 1031 dollars and includes an i7 8700k processor and the same 1050 Ti video card System 1 is 927 dollars and includes an i5 8600k processor and an NVIDIA 1050 Ti video card