The Eclipse AVN6620 is steering wheel control ready and the PAC SWIECL2 is the interface adaptor for it. I have it in stock as well. I want to find out if it is the model that will work with your vehicle or if I need to order in a SWIJACK instead (same thing different software).

Yes the headunit is going to make a difference, a huge difference in the case of a Eclipse.

As far as the speakers go, my bet is that yes you are going to be changing the speakers. As a Infinity dealer, you just heard the reason I do not sell those speakers. A amp with some power would make them come alive, you might want to consider that as well (if you have the room to mount a amp). I would bet that you cannot return the speakers, advertise them here on the forum and someone will pick them up.