Greetings and CNC build soon to start, advice needed.

[Nickhofen]

Hi everyone.

I am Nick from Greece.
I want to warn every member that this thread might contain very silly and hundred time answered questions.

I am an aircraft engeener and maniac selfbuildingmyownstupidthings guy! resently , one year ago, I enter the world of cnc, I bought a new old stock desktop cnc with cutting area 420mmX320mm and replace the motors,controllers and interface in order to make it work.
Υesterday that cnc went to a new house,with the money I get and some designing help from a friend that design 3D printers, I will start soon my cnc router build.
The idea is to build a machine with external dimensions 1500x800mm, steel frame (to lower the cost) two motors at Y axis one at X one at Z, the purpose of the machine will be woodworking and mild metal cutting.
The friend-designer suggest the design below, I know that this is something it has been used at the past at MechMate machines but I do not know if there are any disadvantages since this is not a design that I usually see, what do you guys think?
Another question has to do with the ball screw according to their length, I am thinking to use 1610 ballscrews am I going to have any problem at Y axis since this is going to be the longer one?
Motors are going to be steppers, Nema 34 637oz for X, two Nema 34 1204oz for Y and one Nema 24 566oz for the Z, any suggestions and thoughts are welcome.

Cheers, Nick!