The Spektrum doesn’t have a module bay like OpenTX radios, they want you to stay in their ecosystem not use other peoples. You will have to find a pre made with DSMX or fit a DSMX receiver to any quad you build. They helpfully have a different channel order as well, Spektrum is TAER, OpenTX is AETR.
Alternatively you can sell the DX8 and get something like a Jumper T16 or Taranis with more channels and a multi protocol module (included in the T16, an extra on the Taranis) then you can fly anything you like.
If you stay with Spektrum the tuning and set up of things like endpoints and channel settings etc will be different to most videos, since the majority of quad builders use OpenTX, so you might find it harder to get information. It will fly pretty much the same on either, a standard Taranis hasn’t got any more range than Spektrum or better gimbals etc.