Most of the hatcheries sell guinea eggs. Probably the best rout. If you havent found a local source that is. Check your local craigslist to see if anyone has guinea fowl for sale. They may also have guinea eggs. Problem with asking here is there are people all over the country and world that subscribe to BYC.
I say try craigslist & get some eggs locally--- or in the where am I thread, see if anyone close by you has guineas. Mine are only laying 2 eggs a day (unless I have another hidden nest). This year is so hot I am sure there are a few others that are not laying well anymore.