@xallias that is practically same questions and answers as this other thread started 2-days ago, see:
Recommend that you start by buying ITead’s “Sonoff Zigbee 3.0 USB Dongle Plus” (model “ZBDongle-P” based on Texas Instruments CC2652P radio SoC) (and upgrade to latest Zigbee Coordinator firmware on it before beginning the installation) as then you will should have no problems if choose to go with Home Assistant’s built-in native ZHA integration or third-party Zigbee2MQTT as Zigbee Gateway host application.
Personally I would then suggest at least trying to connect that via a very long shielded USB 2.0 extension cable (that part is important) to Home Assistant Operating System running in a virtual machine (VM) on your Synology 720+ NAS properly configuration for a USB 2.0 port to be used used as a USB pass-through to the VM → Noob - zigbee ZHA vs zigbee2mqtt - #15 by Hedda
If you get that working than you can later migrate to a different computer later if that is want you want.
If want an easier setup then just buy the official “Home Assistant Green” + a “SkyConnect” USB dongle:
Regardless, do more research and read these community guides before buying any Zigbee devices:
- Is Zigbee right for you?
- A to Zig - a Zigbee glossary
- Not many people know that... A random collection of Zigbee trivia
- Zigbee buyer's guide
- Migrating from a Philips Hue Bridge to the ZHA (Zigbee Home Automation) integration
- Zigbee networks: how to guide for avoiding interference + optimizing using Zigbee Router devices (repeaters/extenders) to get best possible range and coverage
- Zigbee #1: where can I find a list of supported devices?
- Mains powered Zigbee devices that aren't routers
- Zigbee devices that don't play nice