I have one of Mac's "The Torch" from late 2007 and need to get an new battery pack. I think it came with the 14.4 NiMH battery pack pushing the Osram 64623 100w.
CPFer LuxLuthor makes the best ones, but hes currently not making any. You can however buy them from wiked lasers website, however they're not as good of quality as lux's. I think they're about $20
I use Tenergy brand smart chargers for my battery packs, they cut off at required voltage, not the highest dollar charger on the market but they have always done excellent for me. I got mine from all-battery.com but they're also available from Battery Junction but they are currently shut down due to a fire. If you're using a 14.4v pack then this is the charger you will need http://www.all-battery.com/smartuniversalbatterypackcharger12v-168vcurrentselection.aspx