for classical music in a theatre and a quiet audience, as the OP mentioned, he wants to go with omni's and to me that makes a lot of sense. not telling you all anything you don't know already, but omni's provide a far flatter response and are going to capture the dynamics, the bass much better than anything directional, and for classical music this is important. plus the openness and "space" you get from a stereo omni recording sounds fundamentally different than directional mics. again this i think is meaningful and important for the type of recordings the OP plans to do.
In terms of my experience having run a variety of omni caps over the years, including Naks (CP3), the Church mics (CA11 mkII) and the Schoeps MK2S, I think there is a meaningful improvement using the Schoeps capsules. Whether it's worth spending a great deal of extra coin on is an entirely different discussion.
The Church CA11mkIIs do have a "bump" in the high frequencies as the Schoeps MK2S does (it's different, though, feel like it perhaps kicks in at a lower frequency on the CA mics, while the MK2S just adds a bit of sweetness at the highest frequencies, you can see the diagram on schoeps website). Either one will help bring a bit of extra clarity to the recording, which appeals to me. I have found the bigger difference between the Naks and the Church mics to be in the lower bass frequencies, where the Schoeps are just plain flatter and cleaner on a relative basis. I have not done meaningful comparisons between the Schoeps Omni's and the DPAs, but from what I have heard from listening to a good deal of DPA Omni recordings, they are very similar.
I am running CA11mkIIs > Tinybox and Schoeps caps > Nbob active cables > Tinybox >M10. Either is great in terms of being very low profile. Hope this helps and good luck...