Hi,
I have both these fish....
The joculator is bullet proof, like said above one of the most hardy and will get about 3-3.5" max...
most joculators come in at about 1.5-2"....
the interruptus is the biggest of all centropyge, reaching 5-5.5" in length...
honestly they are both great fish...
the interruptus atleast in my tank is very personable, like said above.
the joculator is always swimming around picking at the rocks...
i get more "Wows" from the interruptus from people in the hobby and people not in the hobby....
if you want something mega rare the joculator is it, very very few come into the hobby...
the interruptus is becoming more common...
BTW i got both mine from Sedar @ phishybusiness, i assume that's where you are going to get yours from since he is the only one i know bring both in....
if you want a cool idea, get a pair of interruptus that would be sweet!
if you want i can post some pics, let me know.
Nick