Correct tyres for 20” calibre alloys?

[hallix100]

Hi,
So van came with really cheap 275/45/20 on them. I replaced the front first as bad tread left, now I’m ready to get ones for back but wondering if I could have slightly different tyre set ups front and back? I.e front does rub slightly on front, so perhaps move them to back and have slight different on front to avoid rub?

 

[BiTurbo]

Got 255/45/20 all round on mine.
But 255 or 245 /45 / 20 on front and 275/40/20 on the rear depending on wheel width