you'll probably have run a 3mm spacer IIRC under the hat/bell of the rotor to properly clearance the caliper or you'll have to shave the caliper to enable proper fitment to begin with. This is independent of the wheel issue.
SW388s if you're getting them in anything that's is higher numerically than +38mm, you will need a spacer on top of the rotor bell in a 15X6.5 size....I will double check on a DelSol that has done this modification recently if I can find the owner.