I also believe with level matching you'd be happier overall with them mounted on the ceiling, especially considering all of the complications you have with ear-level placement. Granted though, those are some tall ceilings.
The stands do have weights you can put in the bottom of them, but even so, with a young one and cat, I'd be worried about them toppling (not to mention the difficult problem of hiding the wires).
I can't remember off hand anyone here who has ceiling mounted them with that tall of ceilings, hopefully you'll get a few more opinions in the next day or two from folks in a similar situation.
Jason
