Gooday mate....
Expat Aussie here now living in Charlotte NC...
Retired GM (Holden)and Chevrolet
Master tech...am currently restoring a 67 Long Wood bed Chevy.
The For Sale page doesnt see much traffic as those 3100's are really hard to find, at a reasonable price...
If you might like say a 68 or 69 longbed you may have a better chance of finding a candidate...now...
These "finder" companies may actually save you dollars but it all depends on what the truck is that you find, condition, title ( you dont want a stolen truck !)
Over here there is a website
www.craigslist.com that has a Cars and Trucks listing...suggest you stick to southern states like Nevada, New Mexico, Texas etc...anything from up north will be a rust bucket...and these all rust, its in their DNA.
On the Cars and Trucks for Sale, choose a price range, a year range, say 1947 to 1972. the choose Type like Pickup and Truck...
If you want, you can send me an internal IM on this site...for more details...
I dont mind helping another aussie out....