There are a lot of things to consider like, spring weight (I ran 12k/10k), brake pads and driver experience.
Also, Hoosier R6's run wider than 225 - these are essentially the same tire,so they probably also run wide.
Are you dead set on the 15x8? Tire Rack has a set of 15x7 30 et that would be perfect and they weigh 13 lbs,
compared to the 15x8 at 15 lbs

Are you planning on running track events?