Colin with low grade PCa and a Gleason of 6 all contained you have every option open to you. In your case there is probably no huge rush to make what is one of the biggest decisions of your life.
A lot will depend on how you feel about living with the cancer, if you are happy to let the lion sleep within, albeit being treated by RT or Brachy therapy that is one thing, if you really don't feel happy sharing your body with a sleeping lion then you can have it taken away.
There are lots of things to consider like the side effects of all the options and what things are most important to you.
AS has only one real side effect and you have just touched on it, but many men chose that option knowing that they will be checked regularly so that action can be taken as soon as it becomes necessary. They usually have plan b ready to launch if it does become necessary.
True AS involves Regular PSA testing DRE and biopsy so make sure that regime is well explained for you.
Generally speaking Urologists push surgery and Oncologists Brachy or RT.
One thing to consider is the order of potential treatments and that some may become precluded eg surgery is not commonly allowed after RT etc.
Good idea to read up on others experiences but be sure they are in the same diagnosis as yourself.
Read up from the toolkit and now you know exactly what you are dealing with you should be safe to use the internet to research too.
Feel free to ask as many questions as you like on here too there is always someone ready with advice or suggestions.
Best wishes
Xx
Mo