I will hopefully be purchasing a 2003 A4 this weekend and one of the first things I'll be doing is installing a new audio system.

These are the speakers I will be getting, just a set for the rear and front doors:


Here's the amp:


And here is the head unit:


So, will I need to upgrade my speaker wires?
Do I need speaker adapters so they will fit?
And is there anything else I need, other than dash kit, wiring harness, etc?