Welcome to NICO Club! My favorite tire calculator is here: https://www.wheel-size.com/calc/
It gives nice graphics and lets you input data for fenders and such if you want. Anyway, plug in the stock sizes on the left and the new rims on the right, then try a few tire sizes that'll get you the correct profile for the width you'd like. Don't forget to take into consideration the wheels width and offset.
Pictures when done?