Need help with tire sizes

[DDY RCKT]

Hey all! Hey guys, I've got a set of wheels I want to put on my 02 Z06, and they're not stock size, so the tire size issue is once again going to be asked.

The new wheels are 18 x 8.5 in the Front and 19 x 10 in the rear.

Stock tire size is 265/40/17 front, 17x 9.5 wheel and 295/35/18 rear, 18x10.5 wheel.

So what tire width/aspect will keep me closest to stock, and still fit on the rim, and not be impossible to find. I feel like I can use a 295/30/19 on the rear just fine.

Can I use a 265/35/18 on the 8.5" fronts? Or do I need to step down to a 255/40/18?