I would recommend renting a house for at least the first six months to give yourself time to familiarise yourself with the UK, to find somewhere you wanted to live and to make sure it is the right decision for you. At this point in the market you should have plenty of choice in properties to rent. It will be a while before house prices start to rise in the UK and a family such as yours sounds like it will be very attractive to have as tenants so you should be able to negotiate a good price.