I can't do support better than Sharon -- she's a support group all in one woman! But I will add this, with regard to reading up on the surgeries and understanding what is happening -- YES, YES YES!!! I was too sick to understand much of it when it happened to me so I am still kicking myself for some of the decisions that were made early on. At least you know and you have time to plan -- that is very valuable, so of course you should use it!
Also, I can't help thinking that if I were you, I wouldn't want to loose an organ over not being able to get a confirmed diagnosis. Maybe I am missing something, but isn't there some way you can get a second opinion? Or some way you can be surer before you jump into this? Five years remission is great! What if this is just a benign growth? Where my doctor waited too long, could yours not be waiting long enough or looking hard enough?
Only you know you, your real mental and physical health, as well as your tolerance for risk and image altering surgeries. I wish you all the best and sincerely pray that you find answers or are delivered the information you need to help with this decision!