champion is the only supplier for the buick v6 and they can do them for stock regulator and fuel line setups or with a shortened passenger side for external setups
try fullthrottlespeed.com for them
aside from the early fuel rails for the bgc race intake anything else you might have seen would be a custom setup
or you can make your own with bare rails on ebay ...drill for injectors, tap for fitting and work out a method to keep them from popping up