You can run an aftermarket deck and still keep all your stuff, just by the interface for what you have, the deck is the hart of your system, you can only sound as good as your deck allows. With that said, match your speakers to your amp, theres tons of ways to go about it. Im running all memphis pro audio in my truck, i have 2 2 channel amps on my front doors, its just whats your preference and budget.