Hey nav welcome to this exclusive club!
I'll be 70 in Jan. Had open RP 10 days ago and doing fine. I was Gleason 9 at Dx in June after PSA elevated from 2.0 to 6.0 over two years. I had suffered with BP for over ten years so I thought that's what I had now but symptoms worsened (frequency, dribbling). I also had ED caused by finasteride and flomax which I was taking for BP, and I had low T which I was treating with androgel! So I had a few things masking the underlying issue of cancer.
You just have to deal with what you have and not second guess.
I was not a candidate for brachytherapy due to pre-existing BP. I thought hard about IMRT but when I heard I also needed adjuvant hormone therapy, and that the process could take years, I said "no way"! With a high Gleason score the risk of spreading is there and I firmly believe that open RP is best so they can get in and see and feel what you have. I was worried about losing ability to orgasm (albeit dry) so I wanted my doc to spare the nerves if he could, and finding no cancer in that area, he spared them. So after the pathology report came back, I had cancer in the seminal vesicles, none in ten lymph nodes removed, and extra capsular extension (positive margin) of 4mm. with Gleason score 7.
My next step is adjuvant IMRT in 3-4 months.
With your stats, as everyone has said, your options are wide open it seems, and that makes it difficult for you. With GL 7 you are on the bubble. Be sure to get a second opinion on that. My initial was with Bostwick Labs which came up with 4+4=8, then Johns Hopkins (Epstein)which came up with 4+5= 9.
One thing I would say is 100% of the decision should be based on the quality of the practitioner and the institution, not the method chosen. I chose to travel to Johns Hopkins, the number 1 urology hospital and have no regrets. They were awesome.
Good luck and stop worrying: you'll be fine!
Bob