Hi Jim,
I would suggest
http://www.routoutcnc.com , each axis has it's own board so you can buy a X/X/Y set and use the breakout board for the laser control.
I don't really like the 2 motor approach, usually seen on the Y-axis but either way you'll connect each motor to it's own driver board and then have the same step/dir input to the driver. The motors will do just fine if suited to the XY table.
Flying optic lasers generally require a difference setup to a CNC router, although you can use a router base for a laser setup. The laser is more suited to a low mass (quicker acceleration), fast speed system as it doesn't have a heavy router spindle to carry around or need the torque to drive end mills into a workpiece. Generally routers are best built with leadscrews or heavy rack/pinion drivers whereas lasers are more suited to belt drives.
Like I said, it'll work, but isn't optimum. If you already have it, go with it
Zax.