I think those would fit perfectly. They would be exactly flush. The 15x8 +0's are just a bit too far out - technically they aren't flush. Neither are my 13x8 +4 Rota RB's. These in 15x7 +4 would probably be perfect and require just a hair of fender pulling if you are running a low ride height. Cool.
IMO the RB only looks good with the deep lip so the +30 doesn't really do it for me. The +4's are great though.