I've got a lot of rechargeables to handle and I've always had good experience with maha chargers. For your needs I'd recommend the MH-C808M. From the Thomas Distribution site:
"It's like having eight chargers! The 7th generation Powerex microprocessor features a 0.001V resolution delivering just the right charge! The microprocessor that is powering the MH-C808M battery charger is state of the art. It features eight analog-to-digital converters with precision resolution at 0.001V (that's one thousandth of a volt) per battery delivering just-the-right-charge. It's like having eight individual "computer controlled" battery chargers! Users can mix any battery capacity, battery brand, and/or sizes without the fear of overcharging or undercharging. Maha's unique "Digital Signal Processing" noise-reduction algorithms ensure that the signals do not cross talk. This is an Ultra Precision charger. Even the circuit board is manufactured from a reinforced fiberglass material compound. This gives the circuitry in the MHC808M battery charger the ability to withstand temperature and abuse that would quickly render other battery chargers in-operable."
I've been using one for about a year with no problems, and I'm using it to capacity on AA, aaa, c and D charging. I use 8 C cells in our Fanon Megaphone and they alone save us a lot of money.
Get two if you need 16 charging channels. This charger is very well made and will keep you covered.