hi there
if you want a skyline, get a manual..
not only would the drive be better, it would be a lot easier to sell than an auto.
RACV? They dont know jack shit. Their inspection is way too general and it depends on ur luck-if you get a good inspector who's really been in the trade for long(and not just any rookie),u're likely ok.
Get the car to a mechanic you know and have him hoist it up and do all the compression checks and perhaps even use a paint tester.
hope it helps. good luck