I named my son Nathanael from the bible. Not knowing the meaning at the time but when I found out I was pregnant I announced that it was my gift from God, which is the meaning.. gift from God. We all call him Nate the great or NaterGater! He has very strong beliefs and is very stubborn but very loving funny and sweet. He is 22 and the older he gets the more loving he is!
Nate was given to 101 baby boys born in the US in 2012 as a full name. I'd say just stick to Nathan, it sounds a lot more dignified and intelligent and won't sound weird on an older man. And you can always call him Nate if you want to.
I absolutely love this name. I first heard it on "Oprah"! If I have another son, this will be his name - although I have to convince my hubby as he doesn't like it! It is a very strong name & I don't see the point in naming a child Nathan or Nathaniel if you are going to shorten it anyway.