250 autumns probably get 130% more milk over 120 springsMy advice would be to not limit yourself to one ideal in the planning phase.
100ac at home 150 away. Screams 250 cow autumn block through a 36/72 to me. Also 50% more milk.
Knowing nothing of milk contracts in NI, they may insist on Ayr. In which case robots, a ZG and a wagon may be the way to go.
All I'm saying is look at your options.