What? We ARE "unified".
120/240 single phase for residential
208Y120 3 phase for commercial with primarily single phase loads
240/120 3 phase 4 wire for "light" industrial with primarily 3 phase loads
480Y277 for industrial
What's "un-unified" about that?
Well, since you ask.........
120/240 for a start. Residential here is nominally 230V single phase line to neutral. That's it. Cooker, washing machine, lighting, outlets - all 230V.
Same for commercial single phase.
Industrial 3-phase is mostly 400V which is the same line to line voltage from which the 230V LN is derived.
Other voltages are used for higher powers and distribution and I know that's also the case on your side of that wee pond.
But, back to the OP's question. I suppose he can use whatever voltage he wants to. The thing to ponder is still why he would think about getting a motor that is not matched to his supply? It would be helpful if he could respond to some of the suggestions made