For a battery pack try any good brand of premade packs. Venom, Trinity, VIS, Reedy, just to name a few. Ideally you might want to get a pack above 3000Mah, but that is not necessary. I use a Venom 1850 NiCad in mine with good results.

To charge them make sure that you get a good charger as well. I highly recommend the Piranha Digital Peaks. For the price and function they just can't be beat.
[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXCLD5&P=ML]Piranha Charger[/link]

The radio might be a tougher issue. Hopefully someone has already done this to one of the tanks and they will be able to help you there. It seems like these tanks use about five or six channels, motion control, gun elevation, airsoft function, turret rotation, start-up/stop (engine), machine gun fire, cannon fire simulation.