Re: Cab recomendation..
Just some general commentary, since you've already seemed to make up your mind - but it may be helpful for anyone else considering the same thing.
As a utility type vehicle, always go for the extra room, always go for the extra doors.
You may not "need" them - we can learn to live with just about anything if we have to - but it sure is nice to have them.
If you're getting something for "looks", get whichever you think looks best.
BTW, I have a 4 dr Supercab, and I am constantly surprised at how much stuff I can fit in the back - if I have to move all that stuff to the pickup bed (to use the back seats - which are another very versatile feature), it fills up the bed more than halfway (under the tonneau cover that is).
Another thing to think about, with the extended cab, I believe you can recline the seats a lot more than in the regular cab.
2003 Supercab Flareside
4 liter V6
4x4 FX4 Level I
5 speed Auto
4.10 LS Rear