What are you wanting this system to do? Music, movies or both?
The receiver seems like a good one. Denon makes excellent equipment.
I would recommend the EMP Tek 7.1 series and that receiver.
EMP Tek 7.1 http://emptek.com/impseries71_pkg3.php
or the 5.1's. http://www.emptek.com/impseries51_pkg3.php
EMP Tek review http://www.trustedreviews.com/EMP-Tek-Impression-IMP-7-1-2_Surround-Sound-System_review_performance-and-verdict_Page-3
You simply cannot beat the price/performance of these speakers with anything Polk makes.
Denon receiver = $1200 at amazon.
Emp Tek 7.1 = $1,890.00 from emptek.com / 5.1 = $1640
Total = $3090 7.1 or $2840
Slightly over-budget (7.1s) but 100000% worth it. The 5.1's you could always upgrade to 7.1 with 2 more bookshelfs when you can.
Then cables and speaker wire. I would recommend Blues Jeans cables. Excellent products and a great price. http://www.bluejeanscable.com
For some reason, I can't add functional links. Sorry about that.
Apparently they fixed themselves... odd.