Aftermarket wheels, 17" (maybe 18) BBP

I wonder if I should figure radically different offsets in front and back, due to the track difference.

If you are buying aftermarket and have the option, different offsets would make it more bolt on for sure.

If you want cheap and/or used and easily available (e.g. Mustang), you might need spacers in the back depending on what you find if you want to keep your current axle.

Might be worth doing some figuring and determine your current backspacing/offset so you can get an idea of what might fit.