DONT use 25mm ballscrews this is a BIG mistake.? The inertia from 25mm screws is too much for nema 23/4 motors and you'll end up with a very slow under performing machine. Like wise if you go with nema34 Motors then unless you use expensive high voltage drives you'll have underperforming machine due to the slower speed of the motors.
I'm considering investing quite some money into the machine - as I'll be using it for some work I do... So I don't mind kitting it out with good quality motors...

that said, it would be good to see anyone's idea of what percentage of your budget you' should allocate to which part of the machine... e.g. 15% on base structure, 35% xyz hard wear 50% on power, control, motors etc....

So you get the best out for your buck..

any takers?

anyway, I'll take your advice regarding the brackets, positioning, and screws, - but this could change should I decide to invest in more expensive digital drivers?

thanks again for the comments