If you have $850 remaining budget, I would
very seriously consider one of the two following options.
#1 - split the remaining cash among two tower speakers left and right front
#2 - split remaining cash among two smaller front speakers and a subwoofer.
Completely forget about the rear and side surround speakers right now. You just don't have enough $, in my opinion, to get a system that will really please you if you split the money among so many different components.
Regarding brand - you are in the right place for good common sense budget discussion. these guys can advise you well. - But I really think you should avoid the temptation to split the money among so many different pieces - quality will suffer.
I took this advice myself. I bought a receiver, two fronts, and a subwoofer. I enjoyed great sound (music and movies) and never missed the 'effects' of surround. A year of two later, I got a pair of rear speakers - they offer a little bit of an improvement for movies, sure, but I'm VERY glad I waited to get them, because your fronts are what give you MOST of the quality and presence of a good sound system - and waiting on the surrounds let me get a pair of fronts I could live with.
good luck!
regarding brands - in addition to what the gents above mentioned:
I like KEF in that budget. I have those for the rear surround, and they offer good sound for the value. Especially at accessories4less and kefdirect.com .
KEF iQ90 Floorstanding Loudspeaker. Free Shipping on KEF iQ90 Loudspeakers. - cyber monday sale for something dead on your budget.