A few questions.
Is your budget just for speakers and receiver or do you need TV, screen etc. also in that budget?
Why are you not able to audition any speakers? You mentioned a local pro. So, can you audition Boston's and Atlantics?
I am not an expert, but many here would probably tell you not to ignore the room. Make sure to plan for some acoustic treatments to help whatever speakers you buy sound their best.
Also, for such a big space, definitely look to buy very capable subs. Probably big, ported subs, not Sunfires.
What are your listening preferences? You said a home theater, so I assume mostly movies, but just checking.
The more info you give, the better the advice you will receive.