For stealthing, you want cardioids, not omnis, generally speaking. That way you can limit the audience chatter from behind and the sides and increase the 'sound' you get from the stacks/speakers. I would get the CA-11 or CA-14 if you are going with Church Audio. The CA-11 are probably fine, and easier to use since the CA-14s have windscreens mounted on them that you're not supposed to remove.
Yes...cards are typically better for stealthing..as more often than not you won't be in the optimum location where the omnis would work best(better). The cards will help you lock into the sound source while minimizing unwanted noise or chatter.
The statements above are valid personal opinions, but not should not be taken as absolute guidelines for all scenarios. Granted, cardioids work well for many recordists, but others prefer omnis and know how to use them to advantage. The correct choice
for you should be determined by prioritizing the aspects you value most in your recordings and consideration of the efforts you are willing to make to create recordings that you are satisfied with. Different gear and different ears suggest different techniques.
Like many things, the critical element is often
how you use it.