Nothing that special. For the W129 chassis, you need anywhere between 15 and
25mm offset for any wheels going from 7 to 8" width regardless 16, 17, 18,
19 or eve 20" wheels.
If you are going staggered wheel setup, then you will need 40mm offset for
the rear assuming your width size is 9.5"
Discount Tires Direct has some nice AMG replica for sale at very reasonable
Also, you can use any MB wheels you want as long you fall in between the
offset sizes I listed above.