Need feedback for 6k budget

What ever brand and series of speakers you get keep the front 3..left center and right... the same brand and series.

There are a couple of speaker companys that go unoticed by the Agon members because they are not marketed as High End. They seem to be able to make 5.1 and 7.1 etrc systems for a lot less than we are used to seeing on this site. I can't recommend any of them having never heard them.
I strongly agree with Baranowski that you will get a much better value if you buy used. The problem is shipping where some of the better speakers are crated not just boxed and are a PITA to move around. So the second recommendation is to buy local if you possibly can . I know that there are virtual "audio deserts" around the country, If shipping is requiered then calculate frieght into your costs.

Not too much to go on here, but considering the quality of speakers you might get for that price range I'd probably start with a good used pre/pro (i.e. Anthem) and used 5-channel amp since they tend to either work or not, and buy the speakers new unless they're local so I could see/hear them first. When you spend a few grand or so on speakers I think they deserve better than a receiver, especially if music is at all a consideration. I agree with above post that center channel speaker is most critical (probably followed by subwoofer by the way), and for that money you should have many good options. Personally, I'd target spending about $3k on the used amp/pre combo and the rest on the best speakers and sub I could find. Happy hunting and best of luck.

Where do you live? Can you contact me directly at 914-438-4988?

I'd suggest going inexpensive on the receiver (but do get room correction) and bias money to the fronts. nice if the center matches (may not notice if you dont match, I can tell but forget as soon as the movie starts) and save on the rears. my thought is the receiver will or may be obsolete in a few years. also if you get serious and get fancy with a 2 ch system or processor and seperate amp(s) it will be extraneous. good fronts now will be good fronts in 10 years. looking above you can see there's plenty of options or approaches to this problem. Nice sub makes a big difference in movies (more than all but the fronts in my opinion) but you can easy drop a big portion of your money there. you could go cheapest receiver that has correction and a good amp driving things so you are a bit future proof.