Your question was if you can get a Dolby Atmos Experience with in-ceiling speakers. You can't, unless you use the in-ceiling speakers AS Atmos speakers. Otherwise, all you can do is to just hook them up and see how they sound. If it's like most all-in-ceiling solutions, it will be underwhelming. In any case, you will need at least one subwoofer, as those ceiling speakers will not have much bass impact.
It's a VIRTUAL channel unless stated otherwise.