I plan to start selling Bitcoins cash in hand in the future. And I'm also in the UK myself so it wouldn't be hard for me to travel to London. This is for later though when I have plenty of Bitcoins to sell

About altcoins, do you accept altcoins that are not listed on the exchanges you mentioned in the OP?
We will be glad to help selling)
Also we are starting to work with cryptopia, JFYI.
Can you name please this not listed alt coin?