I was tinkering around today and was considering a speed-oriented build with 12 Fetchlands, 4 Steppe Lynxes, and 2 Gaddock Teegs main, plus 10-11 burn spells (with no Apes, Figures, Mystics, Knights, Libraries, or Equipment). I was then considering bringing in a few 0-drop hate cards (Chalice of the Voids and Mindbreak Trap) and one or two copies of various 2-drop hate cards (Null Rod, Ethersworn Canonist, Gaddock Teeg, Thorn of Amethyst), making for about 7-8 sideboard cards total. A good ANT player could certainly play around those pieces of hate with bounce, creature kill, or being smart about Mindbreak Trap, but that strategy may buy two turns, and it seems the deck can consistently deal enough damage in that time to prevent Ad Nauseam, while still maintaining enough board presence to dispatch them if they tried a mini-Tendrils. My sideboard strategy would be to board out your 7-8 copies of Path to Exile and Grim Lavamancer, because the former are dead cards and the latter are too slow, so that sounds like a good number of hate cards from the sdieboard to bring in.
Incidentally, I was also thinking of playing a few REB/Pyroblast effects main because I have yet to face a deck at my LGS that doesn't run blue. That meant I could commit my sideboard to being lighter on blue-hate, while sideboarding extensively for storm combo and graveyard decks. I would count on our superior removal to carry the day against aggro strategies, although at the end of the day, I'm not sure that sacrifice is worth it.
I think if I were to play Zoo next time, it would be a midrange build similar to what you have, but I'd consider just punting the combo matchup. It seems like it would fare well against tribal, blue decks, black aggro, and even Reanimator (fast enough to race, has graveyard hate, and the combination of burn, white removal, and Basilisk Collar on either Grim Lavamancer or a fatty provides enough outs alone).