Six odd loads a week is getting on for double the average use per week, you are going to need a robust machine that will cope with that sort of demand. Also taking into account your "wish" list the best machine IMO would be the ISE 10
built to exacting standards, comes with a ten year parts and labour wearranty covered by local service engineers.
More info behind the ethos and appliances can be found here
on the ISE website.
Anything else would be a compromise.