Hi - congratulations and hang on for the odd looks. Banjo mandolins should be thought of first as banjos and set up accordingly. On Frank Ford's marvelous web site Frets, # he has a terrific introduction to the basic set up of Banjo's. There have been a few threads previously about options for bridges, generally speaking, the wider the bridge foot, the "plonkier" the sound. (That's not a technical term but it seems appropriate.) Scroll down on the above page until you get to the Banjo section.
You have to answer a few questions yourself - what are the height of the strings at the 12th fret? Is the neck absolutely straight? And finally is the head on tight enough to give a level, same tone sound, when the head is tapped just inside from the brackets. You just don't crank down on those little nuts and hope for the best. The head is essentially a drum and the tuning process is about the same. Head tuning, bridge width and verifying the neck angle / offset are the three primary things you need to look at in set up. Frank Ford will get you started in understanding what you need to look for - in an ideal set up.
Mandola fever is permanent.