Drop looks perfect with the sportlines. Although, id be surprised if you aren't running very close to if not on the bump stops. That much lowering defo needs Bilstein B8 or other good shortened shocks to get the full performance from the spring and not reduce lifespan of the shocks.
Wheels look ace too. I see you have 19X9.5 ET30 and 265 width on back. does this not rub? I ask because I have 19X9.5 ET 35 WITH 265/35/19 and they rub slightly on drivers rear. I think even my fronts driver side rubs a little and that's a 19X8.5 ET35 with 235/35 rubber. I'm on OEM Msport suspension