Thank you all for your wonderful feedback! Wow -- I guess I had a front runner in mind, and I know what my other half's preference is and it appears to be an almost equal split between those two based on your comments!
For the nn questions:
Nathan / Nathaniel: His namesake was actually referred to by friends and family as "Nates". I'm not really sure when or why the "s" got added, but I've never heard anyone refer to Grandpa as anything other than Nathan or Nates. I'm fond of Nate but would likely always use the full Nathan if that's the name we choose or Nathan as the nickname for Nathaniel.
I think Ben is an adorable nickname, but I would feel strange using it. My oldest and best friend's (a woman) nickname is Ben (short for a VERY long last name), and I've never referred to her as anything but that in 25+ years. So perhaps that takes Benedict or Bennett out as a fn? Or maybe that's an added bonus?
@raptreverie: I had no idea about "the savior of the south" connection. hmmm. And yes -- you were correct on the sn. If you've noticed my NB name, you will have also figured out that I was a very kind wife when I dropped my maiden name for my husband's. :)
Thank you, everyone!
My favorite is Benedict Nathaniel.
In the order of favorite to least favorite...
Nathaniel Benedict - Very very distinguished. I really like this, especially with your last name.
Nathaniel Bennett - Bennett just don't compare to Benedict to me, but the combo flows nicely.
Nathan Benedict - I prefer Nathaniel over Nathan, but this is still very handsome.
Benedict Nathaniel - I like the flow of Nathaniel Benedict more, but I think there's a certain charm to Benedict in the first slot.
Nathan Bennett - This combo has a very relaxed feel to it, but overall, I'm neutral on it.
Bennett Nathaniel - This combo looks and sounds a little off to me. I prefer Nathaniel Bennett by far.