Have Aesthetic Rhea. Calypso and Atlas Amp Have 12k budget for speakers. Recommendations

Congratulations!
I'd go with Tekton Moabs, and Audiokinesis Swarm subwoofers. There are few speakers in that range can touch the Moabs, and none with the awesome bass of a Swarm. Then I would put the remaining $4k into Perfect Path Solutions Total Contact and E-cards, Synergistic Research HFT, ECT, and Orange Fuses. That'll be one hell of a high end system. Effortless awesome screaming rock, and the deepest tightest bass you ever heard.

With a room that big, I’d be thinking large Magnaplaners or maybe Klipsch K-horns. On the other hand, Tyler Acoustics makes some really nice giants and has free shipping.

Emerald Physics open baffle are well worth checking out. I have KCIIs with upgrades that are fantastic, but their bigger models with 15" woofers should rock

I don’t think Vandersteens are a good match for heavy metal. JBL should fit the bill!!
https://www.musicdirect.com/Search?searchterm=jbl&sort=popularity%7CDESC&page=1&pagesize...

I had the same electronics as you (all Aesthetix) and they were a great match with my ProAc D40r speakers. You can see my room and system, needs a update, but pretty accurate.

I have the same electronics. I use Vandersteen Quatro. Love the combo. Don’t let anyone tell you Vandies can’t rock!

I had the Vandersteen 2Ci, 2CE signature 1, and Vandersteen 3A speakers and all weren’t great on Rock and Rock is my main preference.  I was told by others it is due to the first order crossovers.   There are much better speakers if you mostly listen to Rock.