Hello FarmerBoy and welcome to HW. Sorry you have to be here but you will generally find this is a place filled with folks who are willing to provide both info and support. To help us help you more you might consider completing a "signature" with your age, PSA history, % of cancer in the positive core, etc.
I would recommend that a good place to start is for you to reference the sticky thread at the top of our forum that is designed for new members,
www.healingwell.com/community/default.aspx?f=35&m=2652250. You will want to get as educated as possible about
our disease before making your decision. A couple of excellent books I can recommend are Dr. Walsh's, "Guide to Surviving Prostate Cancer" and Dr. Scholz', "Invasion of the Prostate Snatchers".
Your initial post would indicate that you have very early stage PCa and that is good...it means that you likely have many options that will cure your cancer. You asked specifically about
HDR and SBRT. Both of those options show excellent success in curing cancer with minimal SE's. We have a number of members who have made those choices and I expect some of them will chime in on this thread.
Jim