Blitzcrank bot sounds like a better choice for you, because unlike Leona who pulls herself to the enemy, Blitz pulls the enemy to him. This gives greater opportunity for your ADC to follow up. He can tank a ton of dmg due to his mana shield passive and packs tons of CC with his knockup, pull, and short CD silence.
Nidalee could also be fun for you. Since she's all about the spear poke, there's really no follow up necessary. Her spear does a ton of damage (no joke). You don't have to get kills with her -- just wounding enemy champs, forcing them out of lane, and zoning them is great too. Plus with the S3 changes, AP support is more viable because Kage's Lucky Pick and Hauting Guise now build into something, so you can build AP even if you don't farm.
And yea, Lux bot works great, though I wouldn't consider her aggressive, since her early game dmg sucks. Tons of CC though, and since it's all poke, even if the ADC doesn't follow up, no harm done other than wasted mana.
Fiddlesticks and Ryze also work. Big damage dealers with CC for aggressive types, though lack the poke that Nidalee and Lux has.