Well we know gai is incredible in taijutsu and he got 8 gates.
Kakashi 1000 jutsu, Sharingan, and his own jutsu.
Jiraiya a Toad sage, summoning toads also parts of them and using various jutsu's and various rasengans. Also if he is in Sage Mode he will definitly win, since he can use genjutsu, powerful sage art, and he has the two great toads to aid him.
Still i think it will be tough, but not that tough.
Jiraiya wins with Mid-High diff.