Valfar,

Are you looking to make money from your machine or are you just doing it for a hobby? If you are planning to make money, do not be cheap.

Any lathe has been designed to take cutting forces in the direction that causes the saddle to compress against the bed ways. Even the machines that have a milling head on the top of them take forces in that direction. Using the lathe spindle to mill causes a torque which compresses the one side of the saddle while lifting the other side. Not very good for the saddle clamps and will undoubtedly make milling a pain in the rectum.

Myford users get away with it because they only take light cuts. With the 1440, it would be a waste really.

Yes, you are correct in the watercooled spindle comparison, only difference is that the lathe spindle motor can be 2.2kw and have lower RPM, thus higher torque ;)