I have searched but could not find the answer to this question. Looking at pictures it is hard to tell and I dont have access to each car to simply measure

would the AMG wheels achieve the same look on a 430/500 as the 55/65, or is a drop needed as well?

From my observation, they all sit relatively at the same height, stock for stock, in the same mode. Someone else can chime in with the numbers.

The 55/65 will obviously appear more aggressive with the AMG wheels and AMG body work.

The S55 and S65 have a nominal overall height 6 mm higher than the S430 and S500 (1,450 vs. 1,444 mm). The S600 is intermediate at 1,447 mm. Some of these differences are due to standard wheel and tire fitment and suspension geometry. But don't forget that the S600, S55 and S65 have ABC suspension standard, which lowers automatically up to 35 mm from these levels at high speed. MB does not publish whether an S500 with optional ABC has a different overall height than one with the standard Airmatic suspension.