Brother, as religious and emotional visiting the Holy site is, it is not "advisable" to visit Saudi Arabia for your Honeymoon trip.
go to a romantic place, spend time with each other, get acquainted with your life partner and when you feel the most comfortable, then visit the Holy sites, you can then concentrate on your "ibadah" and prayers a lot more then. Just my opinion.
However, on the other hand, if you and your wife both want to go for Umrah the first thing after marriage, then don't think twice and just do it. Of course, there's no replacement better than visiting the Ka'aba , but it's not very "recommended" for a honeymoon trip.
