Eastman, welcome to HW but sorry you have to be here. Sounds like you have a difficult situation on your hands. I have a couple of thoughts. First of all, have you had your biopsy slides read by a PCa expert like Bostwick or Epstein? You didn't list number of cores or % of cancer in the cores but you want to be absolutely sure of your biopsy results before proceeding.
Secondly, are you totally sure about your radiation comments? Have you visited a brachytherapist (an expert!) to see if that is a possibility? How about cyber-knife? With the chances of colostomy along with other the other problematical issues associated with a surgery I would think you want to be absolutely sure that surgery is your only choice before proceeding.
Good luck and please keep us informed.
Jim