My wife and I are expecting our first child and if its a boy we are going to have a Brit. My wife wants her father to be the Sandak, while I want my Grandfather to be the Sandak. Who should we give the honor to? The Grandfather or the Great Grandfather?

When there is a disagreement it is customary to follow the wife's wishes and respect her, at the first child, and generally. When people grow up they realize that these things are not so significant, but "love truth and peace"(Zecharia, 8:19). Rabbi Chaim Katz