If you want the original look, and no cutting, go for one of those hidden/secret sound radios. These things work off of a wireless remote and the actual radio and disc changer can be in a cubby or back compartment area.
Otherwise, you will be cuting the dash to make an indash one work. I had to cut mine, and off set it by about 3/4" to clear the vintage air system.
A new center dash piece from Paragon is about $90. If you are concerned about originality, remove you stock system and center panel. Buy a new panel, hack it out, and enjoy your tunes. If you ever sell the car put the old one back.
The only problem with swap meet center panels, is most of them are already snapped in the upper section, and if they are not the vendors want as much or more than you can buy a new one. I had no choice anyway, mine had already snapped on each side in the upper portion like 88% of the others out there.