I have such a machine myself (workstation with a Xeon processor) which I use most likely to run VMs on it. That one has a NVidia Quattro FX 4500 built in and Kodi works nice on it. I can't say if your GPU will work fine with Kodi. At least it seems to support OpenGL 3.0 which should be fine according to our wiki.
I will not ask about the logic behind using such a power-wasting machine as a Kodi client, as that's simply your choice. I would use that machine for something different, but that's up to you. This thingy won't even be silent. But yeah, your choice. Just to mention that a RPi3 can do a similar task but will need a fractional amount of power than this machine
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Anyway, in regard of using remotes with Kodi (what the initial question was about), I can always recommend a Flirc:
https://flirc.tv/more/flirc-usb
That's an USB IR-dongle which is able to receive IR command from nearly any remote out there. So there's also no need to buy a specific remote. I use a Harmony Elite with the Flirc as an receiver as well. The interesting part is, the Flirc receives IR signals and changes that to keyboard commands which then will be send to Kodi. So if you press "arrow up" on your remote, the IR-command for that will be send to the Flirc. If you have configured your Flirc accordinglly, then the Flirc will send an "up"-keyboard command (like using the arrow keys on your keyboard) to Kodi. It's really easy to configure and especially in the case if you don't have any experience with Linux at all. The very best part of the Flirc is, that you are able to use it on ANY Kodi client once you have configured it. That means, if it works with your Harmony on "Client 1" you can easily plug it into "Client 2" and it will works exactly the same if you are using the same remote. The config for the Flirc is stored on the device itself. So you never need to fiddle around with the config again if your Kodi hardware changes.
Now I guess you will ask soon which OS you should use on that machine above. At a very first shot, I personally would try Ubuntu 18.04.2. But, given that we don't know the exact GPU you are using and asuming it's the FX 1800, there aren't drivers for that Ubuntu version anymore. So you need to use Ubuntu 16.04. which has support until 2021. But (there will be a lot of "but" if you plan to use Linux) Ubuntu 16.04 uses a pretty old Kernel and I guess, noone is able to predict what quirks you might get by using that on a stone aged machine like the one mentioned above. If you get into some trouble, you might have to use a newer kernel, which could give you other quirks. So in the end...if you aren't familiar with Linux at all and can't solve problems on your own, I wouldn't recommend to use Linux in that case. If you are familiar with Windows, then use that. Reasons for that are:
- you are able to solve problems yourself
- there will be drivers somewhere for nearly any ancient GPU out there
- because of the 2 above, you might get a better Kodi experience
In the end, I still would recommend to use a different machine as a Kodi client. As that's like shooting for sparrows with cannons.