What Lance said is right dude, he was covering the entire model series and engines in his statements, across the ST16x and ST18x series, the FWD and 4WD and the NA and Turbo engines.
The ST185 is the GT4 model, 4WD and turbo (3S-GTE) and was sold in Australia starting in 1990.
You don't need the MR2 as a donor, unless you like spending more money than you have to, as Lance said, a ST182/4 3S-GE half cut has all you need for the conversion and will be cheaper.