I just replaced the head unit in my 35th anniversary SC 2 weeks ago. Here are the details of what I got from Crutchfield:
105KDR610 JVC KDR-610 CD Receiver 139.99 139.99
Check it out. They give you everything you need no charge including the special tool for removing the radio. I chose to not use the amplifier in the trunk so you can bypass it with the special harness they supply. The new radio has plenty of power for all the speakers. The new radio also has all the new features so you can plug external sources into the front panel. The CD player also plays MP3 CD's.
You can get to their website at
http://www.crutchfield.com/
A high quality unit that is priced right.
Harold
PS I would disconnect the plug from the original CD player. Then pull the cable down from the opening where the radio resides. One less piece of clutter to fight when putting the new radio in. I also took the monitor unit out to push the cables around when pushing the radio in.