I am here just to approve all suggestions so far. Only wanted to highlight few things:
Open layout basement, small budget and 90% movies - screams for very efficient speakers.
Ascend CMT340SE fit the bill, but a bit expensive (with shipping)
HSU subs value is really great. SVS also makes good subs, but I have warm spot for HSU
As an option I think you should consider HSU HB-1 Bookshelves and matching center.
I won't normally recommend them for music, but they are great for movies and especially in your larger basement space (speakers don't just play to what you think is "room" - they play to entire open space)