First, contact AZ Z Car to make sure he is actually still selling them. A lot of stuff on his web site is no longer available.
I have debated constantly about the need and desirability of an alum rad. Even if money is no issue to you, it could prove to be a waste of money as well as reliability problems down the road.
Let me explain:
There are a lot of folks (like ZZZZZ in Arizona) who don't think anybody but non-street racers need a big radiator. Most everybody agrees that the stock rad sucks and even some of the aftermarket OEM replacements aren't much better, either.
Like the guy posting above says, you can choose from a number of Chevy radiators that will fit your Z with very little modifications. If an alum rad breaks, you gotta a bigger hassle trying to fix it. This is especially true with a custom.
My advice, get a JEGS or Summit Racing catalog and drool over all the opitons there. Then get back on this forum and get the lowdown on exactly which Camaro rad spec you need. Then choose from the catalog.
Just my .02. Good Luck!