which lipo??

hi all...new to this forum so hello to all. im going to convert my e maxx 3906 to sensorless brushless and like the sound of the mmm combo 2200kv. but im not shure what batterys to use, i mean i want lipos but is there different types of lipos with different voltages? if so which is best to use? i think im going to go with 5s as i like a fast m/t but dont want it uncontrollable. is there any benefit to running two lipo 5s in seires (apart from the mah) or is it best to use one pack at a time? also what about a charger. is there a good/better charger on the market than the rest? do i really need a discharger too? thanks all. its all a bit confusing to me atm.