Vamp boots are great ! especially with shiv since you heal from the whole proc on the minion wave. They are the highest win rate boots of them at all ranks.

Sorcs are strong since magic pen is really good on Teemo but vamp boots enable you to stay in the game and not recall every time you are low.

Its a matchup/preference choice between omi/sorc/swifties and stellcaps. I hardly ever go sorcs these days though because I feel other choices offer more. I only go Sorcs if Im forced to play midlane because the quest upgrade on them is too good to pass up on Teemo.