mill servo conversion ?'s

Hello,

I have an old knee mill that I'm looking at converting. I've
previously converted my Taig mill to steppers using G201's. For this
mill I have some servos I'd like to use. I'm looking at either
Gecko's or Rutex drives. The Rutex drives are capable of more power
but I'm not sure how limiting the Geckos would be. The info I have on
the servos;

Reliance Electric DC Servo motor
NEMA 34 Frame
Model E660
Back EMF Constant, ke = 65 V/kRPM
Torque Constant, kt = 5.5 lb-In/Amp WOW!
Nominal Speed Rating: 1750 RPM
Nominal Voltage Rating: 120 Volts

Encoders;
HEDS-5605 A06 (500 cpr from my searching)

I don't know if that is all the required info, I've tried to find more
on the net with not much luck.

I like the idea of the Gecko's since the accept TTL where I should
convert to differential for the Rutex according to the email I got
from Vladimir.

Any advice on the Gecko/Rutex question (or info on the servos) would
be appreciated.

Also on the Taig the steppers were direct. Can you do that or do you
have to use some sort of timing belt drive? What's the deciding
factors?

Thanks for any help,
Al