What kind of Coilovers/Shocks do I need?

Hey guys, so I bought my truck back in late February of this year from a Ford dealership who bought it from an auction. It had a lot of aftermarket work done to it, but they wasn't sure what it was aside from the obvious (lift/wheels/running boards/etc.). Anyways, I have read on here that people hate spacer lifts and I am kinda wondering why because my truck is riding on (what I assume is) a 6" Pro Comp Lift and it drives better than my moms Camry. In the front it has a spacer and in the rear it has a spacer. So if I wanted to replace the front with a better aftermarket coilover, how would I know what to get as far as length and so on. Also, what about the rear shocks? And how would I be able to tell what kind I have now? (dealership sprayed fender wells with black spray paint so they're covered. -_-) Thanks.

 

i know icon has coilovers for a 6 inch lift..not sure what your budget is though
http://iconvehicledynamics.com/shop...ift-adjustable-front-coil-over-shock-kit.html