Bying a cnc here is stil 20.000 euro or its a old machine etc.
I will go for the supported rails not the bearings.

Now the problem is i still have that big gantry of 3000 mm

How would you guys make that gantry strong so it don't flex and twist?

if its really difficult then i have to turn the machine 90° so the gantry is 1600 mm .