Sorry, no Flying types resist Rock Slide. They will always be neutral.
Skarmory has base 140 Defense, and can definitely take a Rock Slide. Its on Route 45, under Blackthorn City.
If you can trade, a Gligar from the same route in HeartGold evolved into a Gliscor can also take a Rock Slide. Plus, it is resistant to Machamp's STAB.