Do not buy the dual.
Good systems come in time, saving, and planning.
The great thing about car audio is that it does not have to be done all at once.
My suggestion is save for a mid level pioneer or alpine.
It may look like alot now but if you buy that dual I assure you that you will have problems and end up having to buy a better unit... therefore spending more money.
So buy the HU, save for the sub(*), amp, and wiring... then worry about the box later.
Try to get all the components then the Accesories for the stuff will not seem too bad.
If you are doing the install yourself I'd get the wiring from here.
the guy is cheap and is very fast @ getting products out.
Do it right the first time.
and remember that **** poor planning leads to **** poor performance.