Will Keys has a good website. "Will Keys Oldtime Banjo Website" Type into Google should get you there. He leads with his index, not his thumb and does very unorthodox stuff with his right hand. He has a c.d. and a couple of tapes available.
Tom Sauber is another great two finger picker. He switches back and forth between index and thumb lead depending on the notes he's after. Doc Watson uses two fingers as does Reyna Gellert and her father Dan. Most two finger pickers who are after a lot of melody use an index lead. Leading with your thumb presents some problems with getting notes off the first string. The thumb lead has been used more (though not exclusively) for a rolling, chordal accompaniment to singing. Roscoe Holcomb is a good example of this style.
Back to Will Keys........he's my all time hero. Give him a listen and you'll see just how fast and smooth two fingers can go. Order his music and his video from his website. He's accompanied by Barbara Kuhns and Doug Smith on most of his stuff.
I hope you stick with the two finger style. Not too many are learning it anymore with the popularity of clawhammer.
Good luck,
Chip Arnold