A123 batteries are the way to go if you are buying new batteries. Look at the Hobbyking Turnigy 6 or 8 battery charger for an inexpensive charger.
The transmitter pack will need to be removed from the case before you charge it. It is safer, hell I even remove my NiMh transmitter battery when I charge it. The good thing is that you will get 10X more use out of it before you have to charge. Just don't run it down too low and never leave your transmitter on over night [:@]
"the LHS owner claims that the cheap hK batts are junk" Wow I am really suprised he would say that about his competition