ZX4R and XZR400 what is the difference?

Hi to all.

I own 2 offroad bikes( 1is a '82 honda xr500r thumper and the other not worth mentioning ). and I was recently offered a swap on the honda for a 2006 xz4r. After a few confused hours on line i only came up with a few references to a zx4r but loads of references videos and pics of zxr400's of various ages. What is the actual difference if any?

For a start the ZXR400 was made until 1999 possibly a little longer but that was the last model... the L9... so chances are that one was complianced over here in 2006. They are all grey imports so getting parts will be hard, XZ4R was the European name for them I think.
Oh & welcome to KSRC