iXSystems, the company that develops FreeNAS (now called TrueNAS), makes their own hardware for it with full support and decent prices. TrueNAS has also come a very long way in the past couple of years, before it used to be a bit rough around the edges but it's now a very solid competitor especially running on their hardware.
The one potential downside is it's not as beginner friendly as Synology or QNAP UI-wise, but I actually like that about it as I'm not a fan of the UI on either.
The one potential downside is it's not as beginner friendly as Synology or QNAP UI-wise, but I actually like that about it as I'm not a fan of the UI on either.