I would firstly put all that technical speak aside and concentrate on getting the biggest set of front components the car will take. Then decide how you want to power the components; i.e, from the head unit directly or via an amp. Just swapping the components will make a big difference to the quality of sound if you choose a decent set of components. If you concentrate only on the front to begin with you can consider an amp to give them some real up front sound staging.
If you choose components it is wise to remeber the RMS figure that they claim. Then if you decide to amp it up you can look for an amp that offers the comparable RMS.
These components will offer lots of midrange (low - mid range frequencies). If you want a bit more bass you could introduce a sub at a later stage. I have attempted to keep this in plain english speak but if you need an introduction into the technical side I believe the best site is www.talkaudio.co.uk.