1. -Are the engine mounts the same (bolt on directly)
Yes
2. Manual gearbox to fit straight in
No. The 4WD gearbox won't work properly in a 2WD car. Look at a MR2 box I've heard is the best compromise
3. Gear shift levers line up the same
Its a FWD car, the gear shift lever is not attached directly to the gearbox. You may need to modify a linkage or two, nothing major (but due to #2 above, you won't be using the ST205 box anyway.
4. And are the CVs the same (important)
I *believe* the driveshafts won't be compatible. ST185 ones might be. Someone will know better than me on this point.
You want a cheap, reliable, low-km engine? You can't have all three really. If you want it low-km and reliable, it probably won't be cheap. I'd personally *never* fit an import engine in my car without rebuilding it anyway (at least new gaskets and a through inspection)... import motors sit around in junkyards in the rain etc for a long while.. you can get this : http://www.amberaspley.com/gt4/pics/3SGTE/head-rem oval/headgasket1.jpg this was in a 70000km 3SGTE motor.