Thanks Martin for helping me understand the way Hauptwerk loads samples into memory in mono. This is a wonderful feature I am eager to use and experiment with cycling notes and ranks through multiple audio channels.
Thanks to everyone for providing useful information and suggestions.
In the short term, I have set up my system as Thomas suggested and moved the console to the center of the room. This way there is a large "sweet spot" in the room that includes the console location. My wife allowed this because the room is a dedicated music room. I'm using the large speakers against the front wall full range when I have guests come and play. When only I am playing, I use the digital crossover feature on the large speaker amp to send only frequencies below 80 Hz to the large speakers. For one person playing/listening, the higher frequencies go to a pair of studio monitors on stands arranged so that the organist can listen in the near field.
I'm getting a pair of dipole mid/tweeters as Jan suggested to use for listening when only one person is playing/listening. I have a pair of bi-amp-able book shelf speakers that I can use the woofers in the near field and my existing large speakers for the sub-bass frequencies.
In the long term, I want to experiment with cycling mono samples of notes and ranks through several speakers. The way HW handles mono is brilliant. I believe many dry stereo sample sets that are available can be used to load a mono reduction and sound good in my space if cycled through several channels. In this way I can bring the organ virtually to my room and it should sound convincing with no reverberation. There is little reverb in the residential pipe organs I have listened to. I can use my Lexicon if I want to add reverb.
I will start with inexpensive speakers and then maybe move up to omni-directional speakers if funds are available.