"I do not want to be with you anymore."
Translation:Nie chcę już z tobą być.
SVO is subject-verb-object. It is common in many languages (some have it obligatory, like English indicative ) - in Polish it is the most common, although not always, because to emphasise something you can change the word order (but it is rather uncommon and it can look awkward)
The best word order is "Nie chcę już z tobą być." It's neutral and the most natural.
Placing "z tobą" at the end sounds clumsy to me, it's as if it emphasized "with you" - I don't want to be with you anymore, but I still want to be with Michael. I just removed this sentence (because the main one had 'z tobą' at the end) and subsituted it with "Nie chcę już z tobą być".
"już" is pretty movable here.