Gecko 320 vs 340

Being well practised in procrastination I have waited long enough for
the Goldmine encoders to be sold out, both versions.

New encoders offered by USDigital allow a wide choice of resolutions.
With that in mind, what reasons are there to consider the 340 drive,
what is the price to us for the 340 and when will they be available?

I'd like to attain a step of .0002", speed is not important,
smoothness is. The machine is an older Shoptask. I'd like to cut
moorse taper equivalents on the lathe. I'd like to mill scrollwork
decor on instrument panels.
The computer is an AMD 450, and the software probably CNCPRO. The
servo motors will be Sanyo Denki 76 v, 5.5 amp, about 2500rpm.

The specs on these drives recommend no more than 5v over the motor
voltage, and no more than 80 volts. Is there a way to use 90 volt
power supply. (Resistors, whatever)???

Can you tell how knowlegable I am?????

Jerry