We're using:
205/65/R15 on a 15x7J rim - the tyre side wall size is bigger than the standard E30 - they are the same size as you find on E36's. I don't recall the offset at the moment, I would have to check that.
The has 30mm spacers per side - these are H&R from
www.performancealloys.com - could probably have gone with 35mm per side.