I played Kennen only for like a full month and he's my second highest mastery champion so I guess I kinda understand where you're coming from with wanting to play him. However, Kennen ADC is way less fun then playing full AP and is not worth the time invested in learning to play him. It's just a completely different playstyle; basically you are just using your stun for peel and you almost never engage with your ult. If you do you'll just die because you have no Zhonyas, and then your team will lose the fight without their ADC. You can obviously play Kennen, but I think you should try a different champion as an ADC (especially with so many strong ones after the reworks).
If you're set on playing him, the standard build was BoRK -> Runaan -> LW -> more lifesteal/peel items, but you can definitely try Guinsoos somewhere in the build. BoRK probably sucks to rush right now given the price increase but I still see some Twitch and Vayne get away with it so maybe not. The stun actually stacks super quickly once you have your attack speed, but that's after two items at least.