ADM sprinters only ever came with the athsmatic 4AC carby version. The JDM version was the only version to come out of factory standard (discounting the USDM versions). There was a Trueno released here in AUS but was a AE85 model, crappy trim, 3AC, AUTO. Extremely hard to find.
The Ae86 covers from 1983 to 1985 here in Australia. In Japan they cover from 1985 to 1987. All the "hatchback" versions as you put it are sprinters over here, I have not seen a ADM "coupe" (2 door with boot) version here.
John from ImportBitz () is a champ, he imported mine over here for me and I can say without doubt that im more than happy with it. Whilst Breno is correct on pricing (to a point), you wont get a thrashed, rusted out one unless you buy with your eyes closed.
The 4age you see in the papers/wreckers for sale are the fwd version found in the AE82 onwards. IF you buy one of these it requires either getting a rear wheel drive manifold of a JDM hachi, or cutting and shunting the fwd manifold (moving the throttle body to the front and blanking the rear off.
As for the brake conversion, will not be needed as both the 4ac and the 4AG are 1.6l capacity engines. 4AGE is simply fuel injected and a much better engine. and are both good places to search some info too champ