I'm eyeing a lot of options in the forums here and it seems like the ZX6R is kind of a go-to for front end conversions. But are there any particular years that work best? Or were those front ends pretty well the same? I'm eyeing some options for '03 - '06 range for a complete front end. I was reading the "Old Man" conversion PDF that is on the forum here but he never really mentions what year he is using.
ZX9R is longer from what I understand. You still might need fork extensions or a gull wing top yoke. Some people have gone with GSXR front ends but I think they are even shorter than the ZX9R. I went with a 1995 ZX9R on mine and had extensions made up to give more clearance. I still have to be careful going over ramps and bumps or coming down off the curb.
Details in the build thread. Also you can check 'Phoenix fighter',I think he went with the GSXR.
Ya know I think I found a lot of my answers after typing this out. Looks like Cognito Motors has read to go conversion stems for just the conversion I want. For more money they make the complete triple clam assembly for any forks you want. That's pretty sweet.