1+3: i will answer these together...
pyle is on the low end of the spectrum of car electronics, so i cannot be sure on the overall build quality, but i feel confident saying that the screen portion should work very well. depending on personal taste though, you might run into a issue with the headrests not matching your original seats (it would really bother me at least).
and yes, you will need a converter to properly supply a picture to it. in this thread, ripplinghurst highly recommended this startech unit. int eh thread, there is also some details on what kind of poor quality you can expect from a solution like this-- if that is ok with you as well(i imagine your daughter isn't going to care too much as long as she can see her favorite show)
2: yep pretty much..
the dd lcd kit adapts the screen to double din dimensions-- 4" X 7" so it will work with any vehicle, or kit that accepts a double din radio.
also, i am pretty sure that the mp3car store offers both the lcd kit, and the vehicle housing as well. so if you order from mp3car, you can take care of a couple of things at once, and support the forums!