I would say that by far most important criteria in deciding where to live would be the choice of school. It can easily be a difficult enough job here, it certainly won?t be easy from Oz!
You may start at Local Education Authority Web Sites, find the names of the schools and start your search at the OFSTED web site.
You may also try a Map site and try to pick up the school names shown and then make enquiries.
StreetMap - MultiMap - UpMyStreet
You may Post here asking about a particular school but replies are rather subjective.
The school wouldn't register your child without a UK address but you may wish to establish e-mail contact with the school of you choice, asking for advice and enquiring if there are any places available, so that when you arrive on their doorstep they won?t be too surprised!
Contact the school when you arrive and arrange a start date as soon as possible.
School attendance is monitored very closely here; one of the measures of a school is attendance rates. Much research has been done indicating you get better results with better attendance and worse attendance tends to lead to worse progress (quite astonishing really!).
It sounds like your children will fit in fine.
May is the start of the British summer so bring a raincoat, an umbrella and something warm!