You need to look at all the variables, and like you say keep the difference in rolling radius within the limit to avoid tripping the TCS. If you’re going aftermarket then may as well get something wider with stronger offsets to have less of an arch gap
Once you have chosen wheels post them up to confirm sizes/offsets and then the right tyre sizes to suit
Or message one of the traders who will advise and help with the order, hopefully at a better price