Silver - I don't know why I was thinking gold. As for Sam Adams O-fest, it is my favorite widely distributed US-brewed O-fest (my top being mine - no distribution, except my garage, 2nd being Dry Dock's - but the brewer is now opening his own place so that may change).
I would use a "cold-steeping" method for the carafa. Let it soak overnight in cold water, strain, then boil the liquid for 15 minutes of so while you are brewing. The resulting liquor can be added anytime to achieve the color/taste you want. You can even can it and store refridgerated for several months.
I would ask myself "Is it mango first, then beer, or is it Belgian Beer first, then mango" and enter it accordingly. I.E. - Mango first would be in "fruit beer" and Belgian first would be in "Belgian Specialty".
Tom and I almost decided to drive but considering I will just be getting home from 1 1/2 years away 6 days before the NHC I could not see adding 2 - 4 more days to my trip by driving. I am amazed my wife is letting me go at all.