help to choose between KL-6050 and KL- 4030

[p_rabid]

i have 20 kg {{200n.cm min}} holding torque motor 23 nema
4.2 amp
resistance 0.5
inductance 1.8mh/phase
i am working now on 30 volt 6 amp power supply cuz i am was working on the l298 driver
so i am upgrading to one of the drivers KL-6050 or KL- 4030
so i am also will upgrade my power supply when i decide which new driver i will get

the 6050 5.0 amp and the 4030 3 amp and the difference 10 $ since i will be 3 drivers the difference will be 30 $
if i drive that motor with the 4030 it will be okay and get high speed or not
or going for the 6050 the get benefit from the 4.2 amp of my motors

so if the 4030 for 3 driver choose 30 volt 9 amp power supply
and if the 6050 go for 50 volt 12 amp

so any help will be appreciated to choose the right driver and its power supply
thanx in advance