A/V Receiver Recommendation for a newby.

Hi folks. I'll be the first to admit I'm not very knowledgeable when it comes to home theater systems.  I know the basics . I recently bought a  pair of Bowers and Wilkins 702 s2 speakers along with the htm 71 s2 center  channel. I have a pair of PSB GB1 book shelf for the rear speakers.  I currently have an Onkyo TX-NR676 a/v receiver.  I've been told by multiple people that this receiver isn't powerful enough to drive the B&W speakers and am looking to upgrade. I do have a limited budget after shelling out $6000 in speakers. I was wondering if anyone has experience with the Onkyo  TX NR 797 or Denon avr 2600h or recommendations My max budget is $1000.
Thanks in advance.