Find the bumpstop thread by 'jwong77'. It has the bumpstop p/n's you're looking for. Shorter bumpstops won't change the ride height; they'll just give some travel lost with those springs. I haven't heard of anybody's tires hitting the fender liner unless they're too wide.
2007 E90 335i, TiAg, 6AT, ZPP, ZSP, ZCW, 6FL, HD
Quaife lsd, ETS fmic, GIAC s/w, Dinan intake/exhaust/oc, Koni/M3 susp, Apex Arc 8, Mich PSS