I am no expert on this subject. Luckly I haven't had to mess with mine yet. I assume they work like most other cars out there and you can just swap out speaker for speaker. My old Nissan had speakers that each had their individual amps and they where a pain in the butt. I'm pretty sure they don't work like that though. Also if they're component speakers you'll have to ask the tech guys at the store which ones you might need as well.

Really though, any name brand is going to do you fine. Alpine, Rockford, Infiniti etc...