I did get the Andida 2100 mHa battery for the Epic 4G Touch, and while the phone would power up, it would not charge... When the charger was plugged into the phone, a "battery not recognized" message appeared.
So I'm back to my initial plan of getting an OEM battery for SHV-E120L and E120S (international S2 HD LTE) and trying this out. There are some very affordable postings for this battery on ebay, so if it doesn't work, I'll only be out 15 bucks (they are also NFC enabled batteries, which is a plus, but only hold 1850 mHa, unfortunately). I will post another comment if I get one and test it.