IMO it wouldn't be too much of a stomp for either side. Itachi's good with weapons (in fact Sasuke goes to Itachi instead of his father for that sort of training), so it's not impossible for him to set up traps and have the Deva path use ST to protect itself. Then we have clone feints, crow summons, almost instant hand seals, and some Katon jutsu that I assume are just going to be used for distraction.
The Deva Path's not a let down either. Its reaction feats in particular are pretty awesome, and it can both repel and push back its target. It's true weakness is the 5 second delay between this usage. I actually do think that the Deva Path can summon the Gedo, whether it be a plot hole or not. Didn't it already do something before? I remember seeing a panel of it but I can't remember which one (probably when they ditched the cave when Chiyo and the group arrived).
W/o the Gedo I'll give it to Itachi. With it, Itachi loses w/o a huge amount of difficulty.
Oh new stipulations.. didn't see those