Better brakes

I was thinking about upgrading my rear brakes to disc. My truck doesn't stop like I want it to. My brakes are fine for a truck, but that is just not enough. I want it to stop more like a car. I have seen new conversions for around $700. Does anyone know if I can mount rear disc brakes from another application, such as a newer truck? Any thoughts would help. Thanks

Brian -89 C1500

if it were me i would up grade the fronts because they do 70% of your stopping. go with a lager disc and calliper on the front.