Guys, I welcome all your comments, but really didnt mean to cause an argument. Lets just put the subject to bed.

Im in one of these junctions in the road now. Whatever I decide I dont want to alienate myself from advice from either of you.

I must say however, I think wilfy's comment summerises my present thought chain. and as I have genuinely lost, Yes Lost. one of my 3 steppers it was a case of buying two more for the X axis anyway. So simplifying the bits you cant bite (ie the electronics) and only having to buy one (bigger) stepper & a longer belt & some pulleys seems to me a favourable way forward.

Don't have to worry that after 10-12 hours cutting I'm going to find that holes aren't where there supposed to be.!! Or the part isn't actually square after cutting profile out because the gantry slowly racked fraction of degree.!
This machine has cost me an arm and a leg. Im worrying about lots of aspects of it all the time, so Simplifying this area I guess is one less thing to worry about.

On a seperate note; Im also worrying about how accurately I have mounted the gantry to the slide plates. I mean with my Set Square its bang on; when i slide it along the rails; the rails dont move out or in (however I havent yet bolted them down I think im looking to see if it gets tighter at one end) but if the gantry is not square like Jazz has mentioned above the work wont be square... I guess Il find out in time... Its this kind of think that is doing loops in my head everytime im down the workshop. I find myself standing there drinking coffee and smoking staring at it just thinking about (and questioning) the accuracy of my work.