You can search on amazon and other places for accessories for Sandisk Sansa players. I have an Altec Lansing iM413 Speaker system for Sansa,
it can play on batteries or AC, will charge and play a built in radio or accept standard 3.5mm aux audio cable. Others are available, but iSucks
devices are much more prevalent in local stores. Internet searches yield Sansa results.
Good Luck!