For anyone looking at the ZXR400 it isn't hard to get parts, you just can't get them at the local Kawi shop. I get my parts from the UK and a contact in Japan. Everything is still available, just takes a bit longer, though some kawi stuff crosses over you just have too look. I believe the bike Zman has is pretty similar to mine. SP model, with ZX6r front end. ZX6r rear wheel, running a 180/55 pirelli. Lots of room for the width, the swing arm is wider than a ZX6. The 180/55 Pirelli is only slightly larger than the 160/60.
I weighed mine at the last Sears race, It was 335 with about half a tank of fuel.