Hello jarhead! I wasn't a Marine but I want you to know I hold you and "most" others that have served in our military with highest regard and want to extend to you my heartfelt thanks.
Now...to your cnc machine. I don't particularly like them, but a suspended gantry with the machine open on one side and both ends sounds like it might be just what you need. To do a cantelever design like this requires the frame and gantry to be more robust an ridgid so you will need to keep that in mind as well.
Do you have a cad program or cad experience? If not that is also something to consider.
Are you asking for design help, sourcing help/advice?