Hello Gareth and Lynette and welcome to the site.
Was it just those two treatments offered to you.
Was Active Surveillance not mentioned (or perhaps you prefer to just get rid of the cancer - some men cannot live comfortably with the thought of PC inside them)
What about Brachytherapy? No mention of that either?
With all treatments there is the potential for side effects and it would seem from the men on this site that you could get three or four men, same or similar Gleasons, having the same treatment, and they would all have different side effects, so there is no cut and dried "This will give you this or that will cause that".
Download the Toolkit from publications on this website (or approach one of the nurses and ask for hard copies)
The toolkit is a mine of information about the various treatments, how they work and their possible side effects.
You are both young, so you need to research and make sure that the treatment you choose is the right one for you long term.
Unless you have been told that the cancer is the aggressive kind, I would advocate - make haste slowly.
Hopefully you'll get other responses to your questions