Buy Sanyo Eneloop.
http://www.eneloop.info/
According to me and most of my friends these cells are perfect for Tx (higher voltage than normal NiMh and much slower self discharge rate).
> HB L2PE + MMM + Medusa 60-1600 @ 6S A123
> HB LSP + MMM + Medusa 70-1600 @ 6S2P A123
> AE B44 + MM + Medusa 50-3300 @ 4S A123
> AE J82 + SW 5700 @ 2S LiPo
> AE TC5R + MM 6900 @ 2S LiPo