The smartass answer is that anything the airlines don't have is NextGen.
That said, anything that is RNAV/RNP approved is a good start. The Garmin G1000 should qualify. I think what they are really looking for is evidence that are you not just flying a VOR-to-VOR plane or hitting "Direct To" all the time.
One of many lessons about airline applications is this: don't over-analyze stuff.