Hahah, it may have been on of the very few intos that slipped through the cracks. Normally there is at least an admin somewhere to say hello to you.
Which half marathon are you wanting to do?
Rest is the main thing to help you get over your achilles pain. Unfortunately I do not think they make VFFs that large. I think the biggest size is a 48 which fits a foot just over 12". If you could find one in your size it would be a KSO or Bikila. However, I think with your size of foot, you should look into a different minimalist running shoe. Such as, viviobarefoot, luna sandal, New Balance minimus, and merrell trail/tough glove, these are just some of the types that you can find when looking for a minimalist shoe. You will need to transition slowly and could be your time while recovering. I have some tables when recovering from an injury. I will have to find them and then I will repost on here with a decent walk/run plan for recovery.
Wish you the best of luck.