Central Air Conditioning Units

Looking for recomendations on a replacement central air conditioning unit to feed a 3 bedroomed 273 sq meter condo. The current one is huge and probably 15 years old and well past it's sell by date. The current unit is inside the building in a utility corridor, the new one will have to be inside too as can't put external units on this building. If anyone has a recommendation of make, seems there are lots of mitsubishi recommendations, an idea of the price and where you can source them would be great.

thanks in advance for your help