A 120 would be better but an 80 will do. Get the Edge version if you're buying new.
Regarding 3D vs Sport flying .. it's not the style that dictates the ESC, it's the pilot (and setup). Experienced 3D pilots will work an ESC less than an inexperienced pilot. For example, hard collective inputs will pull more current than a piro flip. Also, fast forward flight will pull harder than most 3D "in the box" stuff.
Lowering your pitch is the best thing you can do to ease up on your ESC if your collective management needs work.
Nick Maxwell flies his 700 with a 120 .. the other 99.9% of us need a 160 ..
Team Synergy Factory Specialist / Scorpion / Thunder Power / Byron's Fuels