A cry for help! New Balance trainers

Right, this is my problem. My New Balance MR1063WN 2E are coming to the end of their life and I have only used this type of trainer since I started running as they are the right width for my extremely high arches and have NEVER caused me a problem when running.

 AN OLDER PAIR THAT GOT ME THROUGH GRIM '09

They have now been discontinued and I can't find another pair for love nor money (or indeed a long Google search). They have been replaced with the 1064 which although they look lovely, numerous reviews say that they feel a lot stiffer and aren't good for anything much longer than a 10k.

I have a Half Marathon in Feb and another in March and I have no idea what shoe to buy but I need to get it soon to have a chance to break them in.

I'm not going to lie, changing trainers scares me. I know numerous people who have gone on to develop Iliotibial Band Syndrome as soon as they've tried new trainers and that can't happen.

Does anyone know: a)where I can still get hold of a pair of New Balance MR1063WN 2E trainers in a UK9.5 or b)what the hell I buy to replace them if not?

HELP!!!