Muscle - I have had multiple stereos with 7 band eq's before and it is really nice being able to adjust the sound contours, especially at sound competitions. The 3 band "EQ" is a marketing joke as it is just bass/mid/treble controls, but it shows you the crossover point visually. If $100 isn't a big deal I would go with the 710, but for a basic nice setup, the 610 would easily work. I personally like the idea of having everything tucked away in my glove box as it looks retarded having a flash drive sticking out off the faceplate in my opinion.
Marc70 - Thanks for the compliments. I won't force my opinions of the Sony headunits upon you, but it sounds like you are on the right track - as long as it has a seperate sub out, with a internal crossover(this is crucial in my opinion)and a aux/ipod input, you should be set. Be aware that those 52x4 watt ratings are not RMS, they are peak. The 52watt rating is just marketing as it probably only truly puts out 15-20watts a channel RMS, but as long as your Polks have a high sensitivity rating(say 89 or more) that should be good for 5-1/4's. Regarding just having the Polks in your dash - I think you will be dissapointed as they will be free air and will have no "cabinet" behind them so midrange and midbass output is really quite awful. If I didn't have the 6x9's in my doors for the low vocal and midbass it would sound bad - trust me on this. I would suggest something in the doors if possible, but be forewarned that the carpet will soak up the high's any speaker will emit down there, so it is a good idea to get components for them and mount the tweeters higher. My 6x9's put out little treble as the carpet and padding soak it all up - but the db's in the dash make up for that downfall. Again, personally, I wouldn't go with 12's unless you want to impress the neighbors and that's it. 2-10"s would be plenty of bass in our small cabs and will have less decay with the smaller cones. I am not sure about those shallow mount Rockfords, but in general, shallow mount subs don't have much excursion and you will not hit the lows you may be expecting if you are used to other typical 12's...If I didn't have a gas tank behind my seat, I would go with 2 high excursion 8's(Polk MM840 or JL 8w7's) as they would have plenty of output in a larger box yet not rattle the truck apart...
Feel free to ask questions if you have them guys, I have been helping people with a/v for years..
