I have a budget about $500 (but I'd be curious what I can do for less or for more $)
I would increase the budget so you can include a sub.
Pick one of the pro subs.
Three of these for the LCR
Plus the flat packs
Two of these for surrounds
and the two flat packs
Thats a subtotal of $1524. You could build your own enclosures if you want to save some more money.
You can use the Fusion-8 for all sides and wide/heights. I don't know what Eric is going to release in the future so something better might come up as far speakers go.
If you want to step it up you can go with the Fusion-15 Sentinel for the LCR
and the Fusion-10 MAX for everything else