From what I remember Wilwood does not make a z specific kit, those kits are adapted to the z platform hence why you have an AZ Wilwood kit, Driven Authority Wilwood kit etc. The AP racing makes a kit designed for the z platform. The AZ kit also uses an interior proportioning valve. I've never owned either kit to give a fair comparison but I have driven similar z's with various versions of these kits and I'll say I prefer the AP kit due to the pedal feel and maybe its my imagination but seemed to stop sooner as well, (we never actually measured stopping distances).
" I told my son, you have to catch the football other wise this just looks like child abuse." - My brother