So how about this we do a 1,2,3,4 challenge. 1 yeast, 2 base grain, 3 specialty malts, 4 hops. I suggest (1) yeast US-05, (2) base grain 2 row and wheat, (3) Munich, Cristal 40 and something dark like chocolate or black barley and (4) Cascade, Goldings, Chinook, Columbus.
You can choose whatever you want from either selection but you must use the ingredients from the list in as much or little as you want. Either we leave the style to the Brewer and do a best of show or pick a style and judge from that style. My preference would be the latter but I'm open to suggestions...
EDIT: I agree with
@Jake about the hops we should put a cap on hop quantity.