Yes, do tell them what your truck is so you get the right spindles. 4x2 Edge and non-Edge are different spindle types.
Well, the rear blocks won't give you bump stops if that's important to you. I don't know how trucks without blocks handle that -- I guess the axle just touches; but the Ranger blocks have an arm that sticks out to hit the bump stop on the frame since the axle is placed farther down.
I have the Doetsch spindles and they've been pretty good so far. I've thrashed them some (no jumping to speak of) with 35" tires on them and had no problems but they've only been on 6 months or so.
Putting that kit on will bring you up to about the same height as a stock Edge, more or less.