Swiftness Boots
I think Swifties is super necessary here. It makes it way easier to dodge his Q, E, R, and stay on the side of his legs that are on cooldown. I think Tabis is a bait here, and kind of in general.
Warmog's Armor
I haven't tried building this first or second against Urgot, but I can imagine it might possibly help so that you're never low enough for him to get a good ult on you. Might help with responding to his split-pushing too then, come mid-game.
...
I think you have a lot of options. Heartsteel is likely fine if they have a bunch of squishies, or you could even start Iceborn Gauntlet, or Dead Man's Plate, for more survivability and movespeed or slowing. Bami's item might be fine, though I don't think I'd take it first item. Getting wave control against Urgot will be hard either way, especially if he gets a Black Cleaver first.