Richard,
I want to warn you the the reflection coming from the ground may be considerable. Since you need to walk on that ground, it will be hard to treat the reflections except for a rug or carpet, which you may or may not already have. I say this because of my experience in ceiling mounting my B200s. Mine are roughly 2 feet (golden ratio proportion of 3 feet, actually) measuring from the center of each driver from the ceiling angled downwards towards my listening spot and the ceiling reflections are extremely heavy. So heavy that I can point my head straight up at the ceiling and the vocalist or whatever is in the center is coming from dead on ahead - the ceiling. Most of the instruments are then splayed out along my ceiling, fading towards the speakers as they get closer to them and the reflection distances get longer.
Of course, there is a sweet spot where your ears will be muddled. If the reflection lengths are sufficiently long, then your ears will filter them out. I can do this by backing up my chair to the back of the room. Unfortunately, I do 95% of my listening at my computer, which happens to be within the sweet spot where the reflections are arriving early enough that my ears can hear the imaging as coming from the ceiling because of the confusion between the direct signal and the reflected signal.
