[All_That_Chaz]

Buying wards will make you much less gankable. Of course building tanky will help, but you shouldn't be extending anyway. The way critplank works, a quick Parley/Ignite is enough to kill a half-health character. It doesn't require you to spend a lot of time chasing them. And I feel like if you're building gp tanky, you'd be better off playing Shyvana or Riven. They do that better.

EDIT: I realize a lot of people will scoff at a top without teleport, but GP doesn't necessarily need it because his ult is global, that can be enough to help in a teamfight during the lane phase.