I would check with the different hatcheries. I ordered from Estes and although have the same rule about a 5 chicken minimum per breed they allowed me to order 2 chicks of 5 different breeds. We did have to order 25 but it was very easy to find someone to split the order with. Good luck! I bet some will come back.
ETA Our estes chicks were awesome. All alive and peeping like crazy. Very healthy, haven't lost any (6 weeks later) Did good job sexing only one roo (so far!)