Depending on your budget, Pioneer has some really sweet touch screen nav/blu tooth/gps/sat radio capable that have some awesome eq. capabilities. Here is a link to one that already has everything already in it (the AVIC series) but they also sell the radio and you can buy each piece separately as you can afford them.
If you are looking to install any subs I am sure you have noticed the extremely limited space under your back seat. MTX has a solution that sounds GREAT (I have one in my truck) that you can choose between loaded (w/ subs and an amp already) or with only speakers or just the preform box that you can add your own speakers to (the 10" speakers from MTX are specially designed to perform w/ only a small amount of air space and I highly recommend them.
I hope this some of this helps.