In that scenario you might consider The Emotiva XMC-1. I haven't used it but it's loaded (Dirac, Atmos, etc.) and upgradeable. I've found Emotiva to be very reasonably priced and great quality. I have an XPA-5 power amp and outdoor speakers and both have been excellent. Their service was great too when I accidently left a speaker out in freezing weather they replaced it at no cost, despite it being my own fault!
https://emotiva.com/products/pres-and-pros/xmc-1-0