Maybe you should specify a budget. More money, gives you more options. At this point I am looking at the icharger 1010b+: 300w and 10s lipo max. You'll need balance adaptors, but these are for sale, no custom work required. You can buy this charger at hobbycity, but also in the US at progressiverc. I believe the Neu 10s charger is exactly the same. With this charger you would be able to charge two identical packs(max 5s each) at the same time.

I'm looking to buy this one because of the good reviews it gets, the max power output (>1c charging possible) and the usb connection so you can hook it up to the pc and monitor your packs health(&firmware upgradeable). The hyperion duo is another option which has better specs(12s, 360watts), but is also more expensive.

edit: you could also look at the 106b+, max 6s lipo and 250watts and a bit cheaper. I believe with the balance adpators you can still charge 2 identical packs (max 3s each) at the same time.