If you connect the machines to an outlet strip, there will likely be an on-off switch and surge protection of some kind and a breaker for protection in the event of any major problems. Likely a 15 Amp breaker. I would suggest that you turn on the outlet strip with the machines off and turn them on, one at a time. It is likely that the initial power-on current will be slightly higher than after they reach "steady state". Turning the machine on with a switch rated at 12VDC is probably not a good idea, as the switch is likely not rated for 120 VAC. It might work several times, but I would not do it forever as the results might not be good. Just my thoughts...

Hire an electrician and get it done right.

LTG : )

What lloyd the great said.

Old point of wisdom: if u have to ask, ur already in over your head.

Just go to Lowes and buy 3-4, however many you need, remote control units, you can buy them such that one single remote control will turn all of them on at once.

You need to match the voltage and the amperage, if you don't want your house to burn down.

So you need a toggle switch that is rated for 120 volts AC, and 20 amps of current

https://www.lowes.com/pd/Gardner-Bender-Black-Silver-Toggle-Light-Switch/3379556

Then add an old-school gem indicator lamp above each switch
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If you are going for 'the all powerful effect' of power-up and down, why don't you just get a power strip that can carry, say, 20 amps, (Harbor Fried has a 12 outlet strip for $25) and attach 4 Wifi controlled Alexa outlets- one for each machine. You can then have full programable VOICE CONTROL, such as "Alexa, Turn Jurassic Park On" , or "Alexa, turn ALL machines ON" or "Alexa, Turn All machines off", etc etc

The reason being, you can easily setup Alexa to power up any single machine, or all of them with a few seconds apart to allow power inrush to be lessened. How cool would it be for the machines to power up in order from left to right??? And you can use the machine's actual name instead of just a silly switch. It's all voice activated, the Alexa DOT is all you need ($30) along with power outlets ($6-8 a piece). No electrician, no burning down the house, no hassle, and SOOOOO COOL to have voice controlling it all. And if you get really into the voice control, you can replace the wall switch for your overhead room lights so that the room lights turn OFF, whenever you turn any machine, ON!!!

How cool is that?

I would think you could re-wire the outlets to be on a switch, then either deal with a switch, or fab a toggle switch that activates a switch, like a face plate that mounts on top.
Or
get wifi plugs in's, then custom a switch to activate those wifi plugs on/off.

What kind of walls are in the room now? because romex/wire will need to be pulled to make current outlets "switchable". which, if a hired electrician does this it can easily be $70-100+ an hour. Plus if the furnace is on the same circuit, you'd probably want that moved to its own.
I would opt for a wifi plug and toggle switch mod to save cost and have a fun project.....

If the wire run to the outlet is #14, which most house wiring is, it will likely be on a 15 amp breaker already. If you use an outlet strip with a 20 amp breaker, it might never trip, because the 15 amp breaker at the panel will trip first. And, don't even think about replacing the 15 amp breaker in the panel with a 20 amp breaker, as the wire will not be rated for 20 amps and could get hot and cause a fire, if it is ever loaded to that 20 amp limit. New #12 wire would be required for a 20 amp circuit.

I have my pins on Alexa outlets in banks - Alexa, turn on Pins1, Alexa, turn off Pins2, etc. I tell Alexa to turn them on before I go downstairs, and turn them off on my way back up. Too easy. Alexa turns on my lights and plays my music playlists in the game room too ....