Jiraiya would lose to itachi and kisame even in sage mode, the reason is simple. ma, pa and jiraiya wouldn't be able to look into itachi's eyes bcuz of tskuyomi unfortunately itachi can use genjutsu via handseals and don't tell me genjutsu wouldn't work on jiraiya bcuz of sage mode bcuz the manga never said sage mode makes u invisible to tskuyomi and only a sharingan user can defeat it. Summons including ma and pa would be useless against itachi cuz he will tame and control them like his pet(sasuke controlled manda) besides jiraiya has yet to show the speed like raikage or minato to evade amaterasu itachi alone can handle jiraiya in sage mode but jiraiya isn't in sage mode and needs to buy time into it if he wants to stand a chance against itachi, jiraiya wouldn't make it into sage mode and frog song is useless against itachi cuz he can cover his ears while using susanoo and ma and pa can't use it for too long or they'll become dumb. One more thing, during the sasuke vs itachi fight zetsu confirmed that itachi and sasuke were both out of chakra shortly after that sasuke used kirin and a sick dying half dead itachi who was out of chakra used susanoo for atleast five minites and owned a sannin oro (with his eight head serpet jutsu) who is on par with jiraiya in less than 3 minites, if a sick blind half dead itachi (itachi should be dead but he prolonged his life with drugs) can use susanoo for 5mins then itachi at full power can use it for atleast 20mins just bcuz itachi said he couldn't beat him doesn't mean he can't afterall itachi lied he was after naruto which was not true so itachi was untrust worthy at that time and don't tell me he had no reason to lie cuz he had, want to find out why he lied? Ask me and i'll tell you