Overwhelmed, need recommendations for a KVM

I have a unique situation and am totally overwhelmed researching for a solution to what my setup is having to move to. Hopefully someone here has enough experience with KVMs that can guide me in the right direction.

Monitor config: 1x Arcooda 35" 4:3 monitor (2880x2160), 2x 24" IPS @ 1080p in portrait (flanking Arcooda).

Wireless keyboard and mouse (via dongles).

Primary workstation: Ryzen 9
Dev system: Apple Mac Mini M1 (2020)

Other systems: 4x retro pc’s of various vintage.

I’m looking for either a single KVM triple monitor solution where I can switch the main Arcooda monitor between all 6 systems and the 24" IPS monitors just between the Mac and Ryzen systems, or a two KVM solution as a fall back.

For integrating the retro PCs, I know I’ll have to get some active usb to ps2 adapters as well as active VGA to HDMI adapters which is fine. All of the KVMs I see available on Amazon look less than appealing for the price, or just look very cheap in quality.

Any help/guidance/recommendations is much appreciated. I don’t have any specific budget in mind, I’m mostly interested in good quality and a seemless hot key functionality for switching between machines. The only other requirement is that the KVM/s must fit within a 1RU space.

Have you seen the level1techs KVMs? Level1Techs Store