Anyone know where online to purchase a praying mantus?

I am growing in organic soil which seems to be very tough to keep gnats from coming out of the soil. I would like to buy a praying mantus to eat the bugs but can't seem to find anywhere to buy them or what type of a mantis I would need. I have thought of ladybugs but not sure if they would help or not or where to get them either. If you have ordered from a place online please let me know. As of right now the bugs do not seem to be harming the plant.

Cinnamon oil.

mantis from just about any online garden store.

Got stacks of them in my garden.

Any links? I've searched and most of the sites are so outdated I would be afraid to make a purchase (being many say they are out of stock in 2008 and no updates).

nematodes will eat the larva