Just got my new ZCP rims. Gorgeous. ZCP M3 runs 10mm lower than a regular M3.
I have always run 255/275 35R19 tires on my M3 going back 12 years. Fills the wheel wells perfectly w/o spacers using ZCPs. 245/265 are the stock tires, so this is only 10 mm wider.
A warning...Michelin Pilot Sport 4S rears in 275/35R19 are backordered. HaHa...
Check Tire Rack and America's Tire for availability.
I think 285/30R19s fit as well since the ZCP rims are 19 x 10in rears.
Hankook Ventus are well regarded.
One tip...Ceramic Coat your ZCP 359M wheels during the process.
Full Thread on wheels and tire combos.
https://www.m3post.com/forums/showthread.php?t=475902
Cheers