First, welcome to our club that none of joined by choice! Actually, with a G 4+3, you're categorized as "intermediate risk", which means that you need to act, but not necessarily by tomorrow. You do have SOME time to make a solid decision on which direction to go.
I'd second the suggestion to have your biopsy slides sent to Epstein at Johns Hopkins for a second opinion. His team IS the final word on PC biopsy diagnosis. Your Uro will know how to set it up.
If you tell us where you are, I'd be willing to be that someone in here knows something about
the top people near you. If you're in the US, another good resource is to google "NCCN centers of excellence", which will give you the list of the top hospitals in the US for treatment. Across the US, there is one that is relatively close to everyone.
The good news is, that the word CURE is in your vocabulary--or should be. The presence of predominant G4 is a warning, to be true, which is why you will need to treat soon. That being said, you have every chance of living to a ripe old age.
Again, welcome. At the top of the forum list, there is a 'sticky' thread titled "newly diagnosed". Please read it, and keep coming around.
Age at Diagnosis: 56
RALP on 2/17/15, BJC St. Louis, Dr. Figenshau
58.5g, G3+4, 20%, 4 quadrants involved
PSA 3/10/15: 0.10
My Story: www.healingwell.com/community/default.aspx?f=35&m=3300024