stock sound system - so confused

As some of you may know, i bought this car only 2 months or so ago. I'm looking to buy a replacement factory deck because mine is doin weird things. And yes ive already replaced the amp, didnt help. Anyways, the previous owner had changed the stock deck (doesnt say monsoon on it and it is cassette with no equalizer) and put in the cd player "monsoon system" deck. He also added the AC Delco 12 cd changer. So what system do I have stock? Since I need to replace my deck again, do i need to get one that says "Monsoon system" or can I use one that looks the same but doesnt say it on there? Would it make my system less powerful? I need to find a factory deck, but people keep trying to sell me the one that looks like mine, but doesnt actually say "monsoon system" on it. Tell me anything you know about all the factory decks/amps...

hopefully this wasnt too confusing lol:confused: