Here is my setup. I have had a studio since 1980 so this is my 46th setup. A few details.
Going anti clockwise. Master control on the right with the Mac Studio as the main computer. Yamahah 01V is my final mixer. Monitors are there as well as Faderport 8 and monitor controller.
I have 5 computers. The other 4 are are virtual synths. On the left table is the screen for the Win7 machine in a cabinet below with the drive enclosure also for the main computer. The rack has synths and interfaces and midi interfaces etc. Two mixers on the top mix all the hardware synths and the 4 computers.
Yamaha H&7's as aux monitors. Under that is a monitor and keyboard/mouse which can be switched between the two computers in front of the chair. One is Win 98 machine and the other Win XP. They have older synths on them like Logic ESX24 and all the Sonar synths from Producer 8.5 are on the XP machine. I like the sounds of these older synths/samplers from that era long ago.
Keyboards are Moog Voyager, VSynth, Prophet 12, Odyssey, Korg MS20, Yamaha CS01 (with breath controller) plus tabletop DR Synth. (general Midi synth) Rack has Korg 03R/W, Roland JV2080 maxed out, Yamaha Motif Rack ES, Kurzweil K2000R fully optioned and EMU E5000. The iMac has a lot of virtual synths on it also. All the computers can be sequenced from Studio One. I have 12 hardware synths, 4 computers (treated as hardware synths) and well over 300 soft synths now. (Too many, really all you need is Omnisphere, Unify and Soundpaint! Those three are are 3 computers)
Cupboard has doors removed and hold effects pedals and other things. Including a 1975 Teac mixer which sounds amazing patched over more digital sounds. Up top is ADAT and HiFi amp plus test gear for fault finding etc.. That large aluminium case down the bottom has 1000 CD ROMS for Kurzweil, Roland, AKAI and EMU libraries. The Kurzweil and EMU read AKAI and Roland libraries as well as their own. Very clever. Both EMU and Kurzweil have CD ROM drives attached.
There is a PA in the room driven from a 12 channel Mackie mixer, poweramp plus Turbosound speakers. PA is good for jams etc. The PA sounds as good as my main monitors. There is a sub underneath the main table also. Room treatment does work well and everything sounds great in that room. I have got a large music room as well where I can set up 6 or 7 players. There is an upright in there and room for drums etc. I run a multicore out to that room to record live players etc..