That is his

about the same size as you mentioned.

This is mine

I wouldn't do carpet. Carpet generates static, and if you work on stuff in there and drop a screw or something on the floor you'll curse the carpet. If you do go with carpet, something very low pile. Acoustic ceiling tile will help a lot, you can also get some acoustic/sound absorbing paneling for the walls or make your own from 2x4' drop ceiling tiles and fabric covering.

If you're putting up walls, the easy trick is to alternating offset 2x4s and make a 6" thick wall, that way there is no solid connection between the two wall surfaces.

A big linear power supply like a 70A Astron is a big power hog and generates a lot of heat 24/7 as well. Switching units are a lot more efficient for anything that's going to stay on all the time. Plus that's a lot of heavy gauge wire to run around the shack if you're running a lot of high amp devices on one supply.

Build yourself a good entrance grounding panel and run ALL of your wiring to that panel before going into the room. AC power, internet, coax especially. Everything gets surge suppressed and grounded at that one point. It needs a good low impedance earth ground right at the panel, and then that panel needs to be bonded (outside the house preferably) to the other grounds for your AC power, phone/internet/cable, cold water etc.

Put some thought into room setup and keep in mind the need to access the back of the desks and equipment. One of the best shack setups I've ever seen put a false wall of grid panels behind the desk, with a 3' space behind the false wall for all the wiring and such. Made it easy to access all the wiring and the back of all the equipment while hiding all the mess.

I'd skip the carpet for the reasons mentioned, plus you might get a nice "hall" sound in your transmitted audio.

I worked a station that had some great audio. Asked him what he had, thinking big audio chain. He basically said that he had tile floors in his room.

He had just enough "echo" to sound fantastic.

Corner desk. Then all controls and computers can be within reach of hands on both sides of you. I am building custom cabinets and using standard counter-top. I plan on having a gap behind the counter-top to run wires back into a channel. Also one of the cabinets near the power supply will have a slide out shelf to mount the mobile radios and then run the remote heads and mics to where I want on the desk. Also look at running dual monitor or more so you can log on one screen and qrz or surf on another. I am planning on having a 40" tv mounted above the operating position for viewing or using as another monitor. Tilted down so the operator can see without much strain. You will never have enough outlets 120 or 240. Just face it you will find a way to fill every one. And if you are running wire look at adding some sort of backup for the 120 side and batteries for the 12v side.