I think Orions might be an overkill, though I have never heard them. You will have to travel to the US to listen to them. The Omegas are definitely not the best for rock. For classical, piano, opera, Jazz, they are (to me). I have decided not to have an audiophile system for rock, didn't see much point, given the quality of masterings and that the best rock is usually on bootlegs, not on audiophile grade vinyls or CDs. So I get my rock kicks out of earphones and soundbars.
The only system I know that can do both is that Datasat Dirac Mch 13.4 system with auro 3d. However, you will have to suspend all your learning, experience and perceptions of hifi to audition this. Why?
1. The Datasat dac is poor. Yet it doesn't make much of a difference here, though of course you can improve SQ by putting your dac after the Datasat
2. There is upmixing of 2-channel to the Auro 3d. Upmixing *audiophile shudder*
3. The soundstage is not the style of panels or horns, where you get a soundstage by projecting in front of the speakers for nearfield type listening. You get the soundstage like you get in a concert hall - you experience the distance from the stage yet it is immersive.
4. Separation doesn't come from a preamp being better, it comes from room correction and processing that really shows vocals and instruments differently
5. The front two speakers used were B&W 802D, which I don't like in 2-ch for various reasons, but here they sounded sublime.
6. Best 3d and slam for orchestra I have heard. Want rock? Just switch over to 2-channel and let the propulsive bass rip.
Since you already have box speakers and 2 subs, you might want to look at this. Extension will be fairly cheap for you for ambient speakers, the only cost will be that of a Datasat RS20i (20k), or a Trinnov Altitude, which is much more expensive. You will need to add Mch amps for the surrounds.
Anyway, you don't need to decide. Just do a trip to Brighton. I want some feedback as well, on how this system might sound over the long term. While it did all of the above, it did make the bloom and timbre of some instruments sound different, but I still thought was overall better.