since rb20 doesnt have nvcs i would look at going for a setup which u usually see on rb26's.
most that i have seen have the same spec cams on both sides
but then again ive seen a few high hp ones with smaller inlet ones
SK i leave this to u (or someone else with a rb20)
btw roy for my rb30det ive put in tomei poncam inlet 256 9mm and hks 264 9mm exhaust cam