Im not sure what your thoughts are on infinite combos, but Sidisi has several good ways to mill her entire deck and produce infinite zombies since you run Ulamog.

Aphetto Alchemist + Mesmeric Orb

Cephalid Illusionist + Lightning Greaves and 1 other creature

Food Chain + Eternal Scourge for infinite mana to cast and exile sidisi until you have infinite zombies. Then Dread Return Craterhoof Behemoth for gg. This is the best combo for sidisi by far because it lets you cast any creature for free and it doesn't require sidisi to be in play first to produce infinite zombies.

As for singles Mirror-Mad Phantasm, Hedron Crab, and Hermit Druid are all great self mill options.

Oh boy, those are some pretty interesting combos.

Really dig the food chain and eternal scourge combo myself, may be looking into putting that in there.

Thanks for the suggestions |:)