I was diagnosed in September with very similar results (PSA 7.9; Gleason 4+4). I was also given 2 options - surgery (robotic) and radiotherapy. Given my (relatively young) age of 59 and my health (healthy other than the cancer), my urologist strongly recommended the robotic surgery.
To be honest, one other reason why he may have recommended the surgery was because he is a surgeon himself but I am happy with the choice I made. He strongly believed that I would make a speedy recovery and should the surgery unable to remove all traces of cancer, we could always add the radiotherapy. My surgery took place towards the end of November and I am recovering well, although I do have some incontinence issues. This is getting surely better though!
I do, however, strongly recommend that you insist on a bone scan and MRI. I was offered both and these results really helped me to make a wise choice and to have confidence in my treatment. These scans are also crucial in determining your cancer stage.
All the best!