Hi Chad,
The control card and software are 6 axis ready. Beyond 4 axes you'll need an external driver that is powered seperately. You'll then splice the step and direction to the control card.
The easiest thing to do immediately is add the Gecko driver for the 4th axis and run the motor leads outside the electronics enclosure through the existing chase. We typically use a Wago connector on the end of the 4th axis cable so that the cable can be stowed away when the additional axis is not in use.
With that done, you'll be able to connect to your motor of choice (we've been using Oriental motors off our larger Alpha tools with good result, though they are spendy.) Our online store is opening very soon and, though not on day one, we do hope to offer supplies to help with automated indexing in the not too distant future.
David