Purely because I don't see an issue, yet, in sticking with the bank(s) you currently bank with - why are you looking?
Has your existing bank said they will no longer serve you if you move outside the UK?
My immediate answer is to advise to stick with the bank you already have a track history with because every UK bank I can think of has generally closed their doors to overseas due to the risk and bad media coverage that comes with overseas clients (just look at the news stories of fines being imposed on banks)