Liam,
Looks like there is a set posted for sale by a forum member.
Looks like your Z is a 95. I have a 94 and 98% of tubing, I believe, is the same as early cars. Also, with old tubing you are removing, you will have extra pieces if needed to address the difference.
http://www.zr1.net/forum/showthread.php?t=34360