Hi eric,
What a bummer to be among the rare unprivileged few to be diagnosed at under 40. I recommend you get a second opinion on your biopsy slides from Bostwick or Epstein. You should also read the sticky:
Newly diagnosed with PC? – read this thread first I opted for SBRT because of my (relatively) young age at diagnosis. I figured I would have more years to suffer with the potential symptoms. Because I am still very sexually active, I couldn't imagine having surgery - a therapy that has a high likelihood of cutting off that aspect of my life, especially when there were so many other curative alternatives. Even the 10% or so likelihood of permanent incontinence over so many years of life was anathema to me. Add to that the possibility of climacturia, stress incontinence, and penile shrinkage sent me looking for alternatives. On the other hand, I don't know what will happen in 20 years because there are less than 10 years of data for the therapy I chose. I was willing to take my chances, but others may not be.
The SEs of any therapy you choose will be lesser because of your younger age. And your favorable intermediate risk status (I'm assuming Gleason 3+4 and no sign of EPE) means that all options are likely to be curative for you, including surgery, SBRT, LDR brachy, HDR brachy, protons & IMRT. I think you owe it to yourself to get several opinions before making up your mind. Remember that each specialist knows and will likely recommend the therapy he gives, and will really not know all that much about
the other therapies. It's incumbent upon you to make the effort and seek out their opinions.