1999 PA GM/Delco Radio Swap

Anyone sucessfully swap in an aftermarket double-din radio/stereo? It is just frustrating...the stereo GM puts in this car has both cassette/CD, it has all the fancy features, cool lights, dimming, large clock, super convenient steering wheel controls, and yet suffers from mediocre sound. And...it is quite expensive. (It would be nice to just update the "insides" and retain all the fancy features.) I have seen interfaces that can keep the steering wheel controls on aftermarket units, but the head unit needs a remote input, and for Pioneer that means an AVIC unit (not in my car stereo budget!). Pioneer also makes the din and a half replacement, but wondering if a double-din fits without modification. Thanks.
EDIT...I did a bit of searching on the Pioneer site and discovered there are other headunits with the remote input (especially the new models). A steering wheel interface is also needed. Anyone go this route successfully?