It was a bad idea to bring up the High Z. Should have stuck with just saying 4-axis machine.
I can say this much that im going to use supported rails mounted on 2 pcs of alu extrusions. These two sides will be held together by two (dont know the English Word for it) but two end pieces, watercut alu... Theres much more, i will post something when ive got something solid.
I got this, im sure of it... If not, ill ask you guys... ;-)

EddyCurrent; Yes, i will gladly take some advise for the Electronics part. Thats why im here...