8j

+40s are about as high offset as you'd want to go.

Ideally you'd have

+37 or

+35 region offsets, to give you 3-5mm more clearance suspension side.

Those fitments will fit your MR2, they are a common size set up.

One thing to bear in mind if you're interested

- generally you won't get a 255 rear tyre on without rubbing either arch or spring cup, and an 8.5j alloy is wide enough to take a 245 tyre and lighter than a 9j.

IMO the best compromise between width and weight is 7.5j front and 8.5j rear with 225 front and 255 rear.

Now get up some pics of your new BBS!