As I am investigating into a similar direction at the moment, here are my findings.
For the ZigBee dongle you mentioned, there is one project for OpenHAB 2 . It uses the proprietary REST API to the controller software coming from Dresden Elektronik. I did not find a binding for Home Assistant. To my understanding, the problem (at least from a customer side) with ZigBee is that there is no defined standard when it comes to the API between the PC and the dongle/shield. Furthermore, ZigBee devices might have some product-specific features, and to use that, one then needs the proprietary hub, e.g., like for Hue firmware updates.
Most of the Z-Wave dongles use the Sigma Designs Serial API as part of their firmware . As a consequence it is easier to find a Dongle supported by OpenHAB or others.
So, as a conclusion, OpenHAB and others support the dongle you intend to buy (or maybe already bought in the meantime) [3,4], however, ZigBee support might involve some DIY.