Not an audio expert but I work around a lot of it. One thing to pay attention to no matter what truck you go with is the RMS rating not advertised. RMS is a realistic power output rating that you are likely to see. Matching RMS output with RMS handling capability of speakers, subs etc. aids in having a good sounding system. Not all that goes into it, of course, but a good rule to follow. 6x9's are going to out perform 4x10's IMO. However, 6.5's do very well. I had a set of Alpine SPS600's and they are hands down my favorite speakers I have had. There is a built in capacitor that helps them not blow. I had 4 in an Altima at one time and it sounded like I had a small sub.
This sounds overplayed but you really get what you pay for with audio.
Another good tip is on the head unit. If you want really good sound you need to find a head unit with sound shaping capability and adjustable crossover. Basically a built in EQ. More than just Bass, Treble, Mid like on most units. When you can do time correction, cut off, slope etc it makes a huge difference on sound.
The Alpine CDA 9886 is a great unit.