Hmm tough one because I don't know how durable Naruto's body would be to withstand Hiru Dora.
On top of that, does Naruto have the speed to evade it? Kisame got in a lot of think time while that jutsu was coming at him and Sage Mode Naruto isn't exactly slow.
ALSO Gai can't keep up the gates long, and if they are only using Taijutsu it would seem that Naruto can keep SM longer than Gai can use gates mode.
If Gai hits with Hiru Dora, he wins. So I say Gai.