Generally with normal 4 axis nema23/24 'kits' around 3.5 - 4nm holding you get 2 supplies of 350w each.
So that is 1 supply per 2 drivers/motors.
With nema34's you get 1 supply per axis.

This 48v 600w supply here says it will drive 4 of there 8 wire motors when in parallel. I can't see why one of these wouldn't be fine for yours:
https://www.cnc4you.co.uk/Stepper-Mo.../60HS111-4204F
However if it seems a bit close to max they also do a 48v 480w version which you could opt for, buy 2 of them and put 1 supply per 2 motors. (Or go all out and just get 2 of the 600's. they'll prob run at half power and last for life!)
https://www.cnc4you.co.uk/Breakout-B...U-48Volt-10Amp

Their similar motors they suggest the supplies for are 4A and 3mh inductance in parallel and 12mh in series. Series would require more power.
https://www.cnc4you.co.uk/Breakout-B...U-48Volt-12Amp
I have these exact above motors working on 60v. (I have the 24-80v type drivers)

I'm considering having a crack at building a toroidal supply to output around 55vdc so I can ditch my meanwells and make some space in my control box.