Ahh ok well you do need CNC then. . Lol

Something I was going to suggest regards the design was moving the top rail onto top of gantry beam and using the bearing plate to support the rear plate due to it's height and I see they have done this on this machine. This would be a good design change and if you notice they have triangle plates supporting the tall back plate which will resonate while cutting. Now surface finish won't be an issue for you but anything that resonates for long enough is going to have a negative affect on components etc so reducing it doesn't hurt.