Mmm, you're right. Compared to vanilla Civ4, FFH does have a dearth of very early game wonders that contribute great prophet points. The best thing I can suggest is if you manage to found a religion. Build a temple and assign a priest, since the first great person comes quite quickly. If you then build the shrine, that'll allow you to assign two more priests, which should be enough to get you going. OO is particularly good for this, since its shrine directly contributes GPP too.
Other than that, you basically have to just hope to get lucky with an event. The Amathaon/Ceridwen constellation events give a great prophet to good or evil leaders respectively in exchange for a modest sum of gold. There's also the holy child event which can give a great prophet to OO civs, although that event is non-repeatable.
Other than that, you basically have to just hope to get lucky with an event. The Amathaon/Ceridwen constellation events give a great prophet to good or evil leaders respectively in exchange for a modest sum of gold. There's also the holy child event which can give a great prophet to OO civs, although that event is non-repeatable.