Personally I dont think it matters where you sit Cardiff, you will be guaranteed a great seat and a great atmosphere wherever you are, i believe that there is a family ticket available which might be the kind of thing your looking for, as for a hotel, well good luck most hotels are sold out within about 3 weeks of the event date being announced and you will probably be better trying to pick up a b&b but these are also very hard to get hold of and sell out very quickly, get ready to spend alot of time on the phone or on the internet searching!