For this build, i would go top. As always get as much CS as possible, but you must poke, HARD. Playing very aggressively is the key to making this build work, high risk/ high reward. no matter who you are playing against, you cannot afford to play to passively. Lane dominance helps get you more CS, which in turn helps you come to terms with dropping gold on items you wouldn't normally use in this manner. I assure you, it is well worth it. Movement speed is the key, and that along with attack speed and a bit of ability power might as well make Teemo a burst mage cheetah. As well as being one who can easily go 1v3,4,5 for a fast triple, quadra, or maybe even a pentakill (depending on how fed you are for a penta of course). But to achieve this, you must use his speed as your main advantage, basically running circles around them and picking them off. Master rocketcheetah teemo and you will be glad you did :)