personally, for the most part for a budget of $2000, if you are listening to music a lot, I think floor standing sound better than bookshelf speakers, in my opinion. I am a strong advocate to buy used speakers, you can get higher quality speakers than you could buying new. I listen to a lot of jazz and big band so acoustic instruments for the most part, so I am very picky and have a very hard time finding speakers that can replicate brass sound well. I have not liked anything in the mid range polk.
I like B&W DM series for your budget, can find a pair of floorstanding for around $500 on ebay, center for $200, a couple rear book shelf $300 and a subwoofer for about $300-400.
Also i haven't listened to Emotiva speakers before but have their UPA7 amp and I love it. Emotiva has great return policy so I would say if you have time and are interested buy a pair of their floorstanding for i think $600 and give them a listen, they got a great review.