Toto CST703 Flapper Valve Leak

I need a replacement flapper for my Toto cst703/704 toilet. Any idea where to get one? It looks like the model number is THU112, but I don't see that specific flapper at my local Lowe's/Home Depot in Kansas City. (Do they have one that is compatible?)

A standard 2" Korky replacement flapper for 1.6 gallon tanks will work.

Ok, thanks...I'll give it a shot.