I assume you have read the many posts about this over on the Growing Tomatoes forum here? If so then you've read all the info on how growing conditions affect flavor more than variety and that the actual pH of most all tomatoes fall within a few hundredths of a point of each other?

That said all I can give you is what varieties, when grown in my gardens with the growing conditions I provide, give me that "acidic" (aka sour, sharp, bit) flavor.

Reds: Box Car Willie, Mortgage Lifter, Rutgers, and Earl's Faux

Yellows: Limmony and Russian Persimmon

Dave