I'm trying to look for some good combos to do with my friend. Anyone know any?

I think someone with a good snare or slow, ie Ashe, who can also harass to keep them off you. Another for ganks would be Blitzcrank (Rocket Grab, then you Fling them, enabling you to get them to the tower from farther away. Power Fist and Megaadhesive to seal it.), but he leaves you open to harassment.

Snares and other abilities for early ganks are what you are looking for, I think. Harassers preferable. Hell, even just a pure damagedealer would work if you guys bring Exhaust (with Cripple Mastery). Teemo or Tristana come to mind.

in order of preference; melee carries, followed by ranged carries. if you're dominating the lane like you should be with the poison, you want to be feeding your lane partner kills with the throws as much as possible