Safe Drop Distance?

[advocate]

Hey guys i'm hoping to get some quick advice for lowering springs before this Saturday's meet so that Garm can hopefully drive the springs down rather than have to wait for them to ship.

I'm using Khumo Ecsta ASTs size 205/50/16 on a full stock setup.

I'm looking to get the maximum drop possible without having to worry about permanently damaging a tire on California roads.

Here are some nice high-res photos for you guys to take a look at to see if there's enough room.
http://img198.imageshack.us/gal.php?g=0828090957a.jpg


So I'm looking to get either the Tanabe NF210s or DF210s. The DF210s are a 1.6F/1.8B drop and the NF210s are a 1.1F/1.3B drop.

From the pictures and my measurements there's roughly 2.3 inches in the front before the tire is impacting the top of the wheel well.

On the Official Wheel and Tire Guide this setup is recommended for lowering:
205/45/16 = 23.2* (Most lowered applications)
Problem is i'm 205/50/16.

So my question is are the DF210s stiff enough to not compress and crush my tire under most conditions or do I have to opt for the NF210s and the higher ride height?