I tend to stay away from Unique Cars magazine, because pretty much everything is way overpriced. They will have what you're after, but at inflated prices. You're better off (to find a bargain) in the Tradingpost or The Quokka.
If you do intend to stick with UniqueCars, have a look at the website that goes with it. Uniquecarsales.com.au, they've got everything in the magazine listed, as well as more stuff not in the mag.
Also, talk to a car importer that specialises in importing US steel. You don't even have to go through them (if you do, they'll give you an agent stateside which is handy to check titles and inspect the car). I know a guy who privately located a '66 in California
and had an associate over there check it out for him, then arranged for an importer to bring it into the country. He got it shipped really cheap too, because they had extra room in one of their containers to fill anyway (very rare opportunity for whole cars, but this type of arrangement can be commonly made with spare parts to fill up extra space in a container). Lucky guy. Cobra imports I think they were called, it's been a few years.
A bare rolling shell should only cost you several grand. Well short of $12,000, by any means. Just be wary when looking at US cars (already in the country or not) - Americans tend to half **** even their 'good quality' restorations..
..they usually slap some paint on, re trim the interior, and throw on some period alloys. Lift the hood and it'll be 40 years of spiderwebs, lift the heads and it'll be 40 years of wear.