Usually, DC power supplies have a positive and negative terminal, and the user is allowed to ground one or the other.
It doesn't hurt to check, especially if one terminal is actually labeled "ground".
The Acopian supplies I suggested had neither terminal grounded, with a finite voltage rating between the terminals and the chassis (insulation rating).
If you find a +/- 25 V supply, where the common is not grounded, you can use it as a nominal 50 V supply by not connecting the common terminal.
I have used dual Acopian supplies that contained two identical subunits, with all four terminals brought out for flexible connections.