I've had a couple done by http://garytayman.com/stereo.htm and they are great. They use the Aurora components for their conversions.
I had one radio that was converted using the AAR conversion that a few shops still use and comparing the two, IMHO, the Aurora conversion is definitely better.
I had retro auto sound do mine who was vending at the Carlisle, Pa show. I have no complaints, but for $600 including all the speakers I will just go aftermarket next time (I will not cut up the dash though)