20" wheels on 370z is a bit too big, the car doesn't look natural anymore, the Nismo 19" wheels are by far the best you can do on the 370z, specially with the nismo body kit.
Let's do a swap with your OEM wheels
Papa, take a better photo of the caliper in yellow on a white background and email it to me, I'll do some mockups in PS with the colours you want for the logos.
I need to find my GTM blocking plates somewhere in the billion boxes and pots We can replicate these.
I have this one, which is similar:
http://www.the370z.com/engine-drivetrain/74397-gtm-performance-engineering-high-capacity-oil-pan-w-oil-baffling-system-8qts.html