I don't always play top, but when I do, it's Wukong.
Wukong I always start flask+potions for the sustain in lane and the mana from flask so I can ability harass.
I usually try to come back to lane with a brutalizer then work on hydra. Brutalizer syncs well with Wukong's armour shred from his Q and gives you raw damage to beat down your opponent.
If I'm winning lane and getting ahead, I'll finish pick up hydra after brut, if not I'll build appropriate defense (MR against ap and AR against ad). I'll still wanna pick up brutalizer so I'm still a threat and can do damage when your jungler comes to gank.
Even if there is no tank, I'll still continue to build damage items on Wukong because his passive makes him naturally tanky in team fights.
I NEVER get sunfire cape on Wukong, it breaks his stealth from his W and at a distance a fake can be told apart by the aura its missing from sunfire (buffs don't appear on decoys either).
My build path, assuming I'm keeping up or ahead, would be brutalizer>hydra>finish ghostblade>black cleaver.
After cleaver, look at the situation and see if you're easily killing or easily dying, if dying build defense, if killing grab last whisper. With those items and going cheese their team should be shredded of armour. (And pick up and finish boots as you see fit, need more def. then finish boots or wait til laning phase is over).
When it comes to Teemo, you'll outscale in late game and once you hit 6 hes dead. You can trade and bait his blinding dart with an E then quickly use decoy and go back to normal. Naturally he'll want to use his Q to avoid further damage. If you see your opponent falling for this take advantage of it, not just with Teemo either. Once you hit 6, you need to bait out his Q then go all in while its on CD. Grabbing a mantle early will help as well, but don't need to turn it into treads because spending your gold on damage should be the priority when its Teemo (unless you've fed, then go defense). You'll get bullied definitely because of his range, but farm what you can and trade if you can trick him into going off on your decoy.
The decoy is an underestimated ability of Wukong's, I suggest taking advantage of the stealth and trickery potential.
Just my way of playing Wukong (and has been working so far).