Level 3 gank is probably possible, but I think that apart from shaco, that's just plain inefficient in terms of clearing. I prefer pots start to prevent counter-jungling/unexpected encounters from costing too much in my jungle. While I don't really have a qualm with you getting two levels in shield, I still recommend strongly taking q first, as it gives you the most damage boost, especially if you're running AS reds, where the AS will greatly compliment the AD boost.