You'll need to budget quite a lot for the miscellaneous bits and pieces.
How are you going to hold the work on the mill table - you'll need a vice and/or clamping kit.
You'll need the milling cutters and (I'm not familiar with that mill) whatever the mill uses to hold the cutters - perhaps collet holder and collet set.
You mentioned tramming - yes, you'll need a dial indicator or similar to measure for squareness - and whatever you're going to use to hold it (potentially it might fit in one of the spindle toolholders, or you may want to use a magnetically clamed arm. You might want someother measuring kit also
Do you want to control spindle speed from your Mach3, or manually? You might need more kit if you want to automate this.