Rover SD1 wheel offset

[sliller]

Iam looking into new wheels for my SD1.
Does anybody know what offset the wheel should have
and what will fit under standard arches?.
I think its 8" wide at the front and 10" on the back??.
Also on the same subject, the PCD for Rover wheels was
127 x 5 I think, now porsche have 130 x 5, can I use
Porsche wheels?.
Cheers