Sasuke wins decisively. Jiraiya may be able to drop toads on people, but remember: Susanoo can be manifested FAR faster than that toad can drop. Itachi summoned a Susanoo so quickly that it blocked a lightning bolt (Kirin) that hit in 1/1000th of a second. No way in hell that toad falls as quickly, or has the same striking force. Sasuke's Sharingan would read Jiraiya's handseals the moment he begins, warning him of something coming to begin with, causing him to get outta dodge with a well timed Shunshin or activation of Susanoo anyway, so that's definately not the gamebreaker here.
If Jiraiya were to result to summoning Bunta, Hiro, or Ken, Sasuke'd simply do what he did with Manda: Genjutsu them into subjugation. Maybe he kills them right off... maybe he forces them to attack Jiraiya. Either way Jiraiya's toads pose little threat.