I like your list for a rainbow. To narrow down to 5 I would exclude RIR, Whiting, BR and add a Maran's (Cuckoo will look like BR but give you dark brown eggs.)Here are some that we liked from catalogs/family friends:
Rhode Island Reds
Barred Rocks
Orpingtons
Americauna
Easter/Olive eggers
Whitings (true blue/true green)
Leg Bars