Thanks for the comments everyone.
The reason we chose to go ahead with HSBC despite the fee they charge is so we can have the accounts set up now. We want to start transferring money and we have 4 months until we go. Plus we have a huge amount to do between now and when we leave so we're happy for them to deal with the paperwork.
It will save us having to mess around sorting out a bank account once we get there. I'll do some investigating when we're there and we could change banks at some stage if necessary but this will get us by for now. Once the cards have arrived I will change the address of the UK accounts to a friend in the UK so that by the time we get there we will have 3 months of bank statements with a UK address. That should make it easier to change to another bank if we choose.