Need help building a robotic arm.

Never built a CNC robotic arm before and can’t really find much info on the web from people that have built any,so here goes. I have a small company making composite parts and I would like to design and build a CNC robot that could spray paint inside a box that measures 800mm long by 500mm wide and 500mm high, at the moment we spray them by hand but the problem is it comes straight back in your face so it’s a bit of a pain in the ass. My idea is to build a robot that could spray inside the boxes using readily available motors/controllers that did not cost the earth and as many standards off the shelf parts that could be used. I would like to build it in composite as I have a lot of experience in this field and I would be able to make moulds and replicate it when needed. Don’t know if I would be just wasting my time or if there could be a way of making something like this work that’s why I’m posting here.

What I need

1) Robot that can spray as mentioned above
2) Would like it to be bench top mounted with arm going in the box
3) Would like it to look like a industrial robot (Look good for any potential customer walking into my shop)
4) Does not need to be 100% accurate or would be a problem if it has some backlash etc
5) Built using cheap and readily available parts
6) Somebody that has experience with building CNC machine as a hobby and know what motors/controllers would work best (I am hope- less with eclectics)
7) Somebody that knows where to find all the parts and is up to date on building CNC machines in general
What I have and could do

1) Have my own composite shop and a lot of experience in composites
2) Have a lot of experience in 3D design and modeling
3) Have a CNC router to make machine plugs for composite parts
4) Have a CNC lathe
5) Could give free composite parts to someone that worked on this with me
6) Could supply the composite parts to someone that had interest in selling the robot as a kit
7) Could make a blog and document the whole project from design to working madel

Am I asking too much? It would never work? Am I crazy?... Feel free to comment any advise would be appreciated

Thanks

Darren