Ok.....dammit!....

this is precisely the reasons I went with the method I did....which is the stub adaptor and Audi strut cartridges...and when finished mine is almost identical to teh lowering height as yours...if not slightly lower.
Here was the gist: Lowering by about 1" in the front end.....lifts the rear end slightly as the body pivots around the rear axle. With teh Audi and stub mod...the front will then be just slightly lower than the rear....if you have good rear shocks.
Very slight mods to the upper rod threading on the rear shocks and the lower mounting bolt hole gave me the ability to level everything.
It pretty much looks like what you have and I can send you a picture if you want.
But...and here is what also helps.....I use 5.5" wheels and have 205/60 -15's on it. They have sidewalls that are about 3/4" lower than stock tires. That really helps the handling and the visual.
I noted quite a while back that lowering the perch...has this risk....and thats just in straight line driving. Going over bumps at compression is a heavy risk and will damage tire, suspension and possibly the inner fender well.
Several things you can do:
As noted, you can get a spacer for between the wheel and rotor. Test at full strut compression and at all turning angles to find what you need.
Also, at the moment...I use 205/60-15's on the aftermarket 356 style chromies you see in the magazines. The offset is nearly perfect and may work better with what you have. Check the offset of that wheel you are using.
Last resort...but it will work well. It appears that the lip or edge of the strut is the main issue and not the spring itself. You can grind away that outer portion and even scallop a bit into the spring seat area....with no negative effects to the spring seat. That may cover what you need. Hard to tell from the photo.
Personally...I would find a new pair of strut tubes and work from teh other direction. Ray