Help me build my HT

Hi everyone, I’ve been wanting to build a home theater (non-dedicated room) and I think it’s finally time. I want to integrate my current 2-channel setup and start with a 5.1.2, with room to upgrade later. I need something modern with good sound separation and 4K 120Hz support for PS5.

Current gear: Speakers (owned): • KEF R3 (L/R) • KEF R2C (center)

Speaker upgrade options: Option 1 (~$1,200): • 5 × SVS Prime Satellites • SVS SB-1000 Pro

Option 2 (~$1,800): • REL HT/1205 • KEF Q150 (surrounds) • KEF Q8 (rears/heights)

Amps (owned): • Rotel RC-1572 MKII • Rotel RB-1582 MKII

Looking to buy: • Onkyo RZ50 (concerned about age and sound quality) • or an affordable processor (I can add the extra amp) Budget here is: $2,000

TV: LG C5 83"

Thanks for any suggestions!