Collin,

I am pretty sure the 750W is enough since you are going to gear it. The 1.5kW however for $90 is not a bad deal. I know that GSK controllers and Servos work well together and you will get decent support for them.

Just be warned that the 980MDc and any 980 for that matter requires a bit of ladder tweaking and macro writing if you are planning to use repeatable Z tooling like the stuff I sell.