To be quite honest Im still pulling myself back together after reading Jonathons post
take it easy man :)
be assured that most of us start pretty much where you are
i think some posters on this thread are being a tad unfair in flexing their intellectual muscles without remembering what its like to wade up to their neck in information and the inevitable burnout that causes... reminding you to chill should be on their list :)

you have a lath/mill so its safe to assume you are a practical bloke... if you have the gumption and time and a little help, nothing will stop you designing building a machine that will do as you require... it doesn't have to be rocket science and most machines are built without the in-depth mathematical analysis.

it wont be long before your the one sharing the love and helping some crazy arsed dude on a mission to build a cnc (just try not to melt his brain lol)