An even better deck would be Kingdra/Floatzel GL Lv.X. Sure the cards are harder to get than the Walrein line, but the reason I say it is because your entire deck really relies on that Walrein's Poke-Power. And if you're using this deck for Infernape 4, well then you're asking for it to be Power Sprayed. Kingdra is faster and doesn't need as much Water Energy in the deck. And I still expect Gengar to be popular everywhere, so then they'd be able to easily hit you and you'd have so many other Powers like Starmie, Claydol, maybe an Uxie.
That's my insight on what to play if Infernape 4 is getting big in your area. (But if there seems to also be a lot of Luxray GL then Walrein MIGHT be the way to go)(Or just something with Machamp XD)