I've looked at some expensive KVMs, software control of display inputs and other stuff. Bottom line is no, there isn't a good solution of this. There are a bunch of limited, glitch-prone things you can do, but what you're thinking of doesn't exist yet.
My expectations for such a system are as follows; connect an number or computers (3-4 minimum) in arbitrary ways to a number of displays (4, minimum) and a set of input devices, without a.) lag b.) glitches c.) limitations on resolution, refresh, etc. Lag can be no more than a few imperceptible microseconds. Glitches include input devices not being recognized, causing hosts to have driver conniptions when switching, displays not getting signals, and other typical KVM behavior. All of this must happen using a single button press to switch among programmable configurations, and configuration done with a high quality native GUI on whatever platforms I happen to be running. Oh, and audio.
Modern displays usually have multiple inputs, and some of them even have non-shit firmware that switches between inputs quickly and without a bunch of mode-setting drama. The problem is there isn't a good, universal way to control this from software. There are some creepy, half-supported utilities floating around in freeware/shareware land that work with some displays. Barring that the current state-of-the-art is wearing out the input select button on a display you may not be able to reach...........
I wouldn't hold your breath either. Its going to take a few more years before it dawns on manufacturers that the desktop market hasn't actually died. Right now they're in table/laptop/phone mode and — aside from g-sync and other gamer stuff — there isn't much innovation going on with desktop hardware.
If you're willing to be very selective about your hardware and spend some money, particularly on your displays, you can almost get there. You'll need an active USB KVM system like ConnectPro, displays with a generous number of software controllable inputs, and you'll need to be to be prepared to deal with all the sundry glitches your creation with make you suffer.