to build a lathe indexer

[woodman08]

I need some direction on what componets to buy to build a lathe indexer ( i enclosed a few photos of what i am trying to do)
I have 3 axis cnc now and would like to add a 4th axis and the hardware.
I have gecko drives G203v and would purchase the same for the 4th.
I do not know what nema rating my steppers are .
The id on the stepper make no sense...y-86hs114df05d, x-90hs78de062d , z-90hs78dec62d
The x and z are 8 wire 9cmx7.8cm high,the y is bigger at 9cmx11.4cm approx black in colour
I have an antek power supply AN 8445 201 955 0800 not sure if this will support a 4th axis.
If you can and i would appreciate if you can advise me on what stepper to order with the G203v drive
and will it be ok with the power supply i have.
I intend to work only wood and the size would be around 8 in diameter 49 in long
thanks