Rotiform Cast BLQ Wheel 18” Machined silver

Hey guys, hope you all had a safe and restful weekend!
I am planning to switch out my 235/40 R 19 92H stock rims with Rotiform 18x8.5 et35 5x100

At the website of UroTuning I have the option to choose different sizes on a drop down Menu. See attached image.
I just goggled my Rim size and Bolt pattern;
19x8 ET48 5x112
Can anyone confirm these numbers? Would that be my actual rim and bold pattern that I need to get?

I understand that I’m downgrading from 19” to 18” rim. My question here is, do i need to get right at my +40mm offset here? I wouldn’t mind being a little over (not flush) if space and Performance allows it!?

Thanks so much in advance! Would love to hear any suggestions, and or opinions 😃😎
Much appreciated!