I use the paraboards from EP buddy, they are an excellent solution.

To further expand you question, you can charge ALL your 2S packs together. So using your example you can charge two 2s 5000mah packs, and the two 2s 2200 mah packs all at the same time. Charge current is divided evenly across all the packs. Setting your charger at 20 amps (max continuous rating for para board) would push 5 amps into each of your packs. So you would be charging your 5000mah packs at 1c and your 2200 packs at about 2.3c.

The key points to remember is that the voltage (cell count) MUST BE THE SAME, and the charge current is evenly divided between the number of packs charged.