I am now in a position to join the Knights Templar and the Hospitalers. I have also been romancing a woman with the intention to marry and make an ally of her family.
However, these goals are mutually exclusive, so I'd like to know what the benefits and downsides are.

Question: What are the benefits of joining the Templars or Hospitalers? Do I get access to better armor and weapons? Can I recruit new troops?