Bridgeport stepper setup with RC-500

I have a Bridgeport Series-I that I have removed the old (working) Boss-6
controller from and replaced it with an AHHA RC-500. I'll probably have a
series of questions as I travel down this road but the first is:

My Series-I (1981 vintage) has 8-wire steppers that were jumpered as 6-wire
(unipolar I assume) on the Boss-6.

Should I wire the coils as parallel pairs or series pairs?

What current setting should I use on the (12 amp max) RC-500?

As I recall there is a tradeoff between max-speed and torque but I can't
remember the details.

Does anyone have recommendations as to the initial settings for max step
rate and acceleration with this hardware/software (Ahha Artisan) setup?

This is a home shop application.

Cheers,

Chuck Hackett
Omaha, Nebraska, USA
7.5" gauge UP Northern 844