If u go for ET30 and 5 mm spacers then Drum side will be 1mm shorter than stock and Curb side will be 16mm longer than stock. Get a flat stick across ur rim over lapping towards wheel arch and measure where it will be if ur rim was 16mm out. I'm sure they still wont stick out of the arches
I have 16" Abarth wheels 6.5J/ET35 and 12mm spacers front and 16mm back, u can see before and after pictures on my thread on page 4