Tokico's are off Japanese Superbikes etc, Speedmerchant make an adapter to bolt the straight onto the fork leg. Can even use stock Master Cylinder.
I put the rear brake off a ZXR1000 on the back of my chopper and it was unbelievably strong.
Yeah your right, I have several jappa calipers I bought thinking they would fit with no joy.
In the end I just bought a set of solid spoke rims and now I can run any caliper I like.