All machines have backlash, you are not looking at $250,000 machining centers here. That is a sieg x2 you are looking at they are decent machines for there size and everyone and his brother sells there version of it just a different color and some are a little better QC(some are and picked by a agent in china) all though the same machine. There are some simiple mods out there to keep the backlash for getting out of hand like the double nut or split nut methods.
Also I don't understand your request on the differenece between metric and standard, in the states you are only going to find standard unless you special order it. All your material for the most part comes in fractional sizes anyway so you save your self some headaches in measuring.
Chris |