the competition for the entry level speaker bundle you mentioned is this pair from Jamo at Vann's (an excellent on-line dealer).
the Jamo 506 bundle http://www.vanns.com/shop/servlet/it.../jamo-s506hcs3
the Jamo 606 bundle http://www.vanns.com/shop/servlet/it.../jamo-s606hcs3
and yes, you can add two additional bookshelf speakers for the "rear" speakers in a 7.0 setup (if you have sufficient room behind the listening position for true rear speakers). And you can add any competent powered subwoofer (or two) to the mix when the budget supports the extra spending.
The Onk NR609 is a nice unit, with built-in networking and internet radio (which is a real plus).
the Jamo 506 bundle http://www.vanns.com/shop/servlet/it.../jamo-s506hcs3
the Jamo 606 bundle http://www.vanns.com/shop/servlet/it.../jamo-s606hcs3
and yes, you can add two additional bookshelf speakers for the "rear" speakers in a 7.0 setup (if you have sufficient room behind the listening position for true rear speakers). And you can add any competent powered subwoofer (or two) to the mix when the budget supports the extra spending.
The Onk NR609 is a nice unit, with built-in networking and internet radio (which is a real plus).