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. 
The Onkyo 797 may be a small bit better, but it's still not going to be as powerful as other's recommend.  The obvious recommendation would be to add an external amp, but these Onkyo receivers do not have analog pre-outs.  It's unfortunate.

A $1,000 is not going to buy you much. 
Whoever told you its not powerful enough is full of it. Those are 90dB speakers. They will be just fine with as little as 20 watts. Your receiver has a lot more than that. 

Power however is one thing. Quality is another matter altogether. Your speakers will sound a whole lot better with a good 20 watt stereo amp than they ever will with any AVR. 

Quality also is a lot more than speakers and amp. Interconnects and speaker cables make a big difference as well. 

Before looking around you need to decide what exactly it is that you want. If you want all those channels then you are doing just fine. Your AVR has all the power and channels you will ever need. If you want quality though then you will want to look elsewhere. No AVR ever made has good sound quality. So it all depends on what it is that you want.

My 12 year old Onkyo HT receiver has better "SQ" than any movie theater I've ever been to. Alas, I've just learned that isn't good enough.
I would say ht is  about 70% of my usage and 2 channel music listening the other  30%. Thanks.
Buying a used Anthem MRX 520 (or similar) is likely your best bet.  Then look for a good 3 channel amp in the future to use for your front speakers.  The Anthem AVR receivers have analog pre-outs so that you can add an external amp anytime.
Thanks Aux. I did research the Anthem per your recommendation.  It does look good. However the  520 doesn't have Dolby Atmos or DTS X which I've switched most of my movies to 4k ultra with one of those two as the  sound format. I saw the next step up the 720 does but is around  $2500. I'm very naive about preamps to be honest.  Right now I'm bi-wiring and bi-amping the two towers. Was hoping maybe the Denon 4500h would be a vast improvement over what I have. Thanks so much.  I may wait a few months and save for the Anthem if you guys feel it's worth the $1,200 money difference. My wife wants me to get something that will last for  5 years or better.
For your information, Dolby Atmos and DTS:X are not hard requirements.  You can play a Dolby Atmos movie through a normal non-Atmos processor and it will work just fine.  Both formats are fully backward compatable.  I would say that you really only want to get a Atmos/DTS:X receiver if you actually want more than 7.1 channels (and height channels). 

The big problems with current compatibility are the 4K and HDR requirements.
Just because “other” people say you need a more powerful AVR doesn’t make it so.  If you don’t sense any distortion, strain, or lack of power you’re probably fine where you are.  Onkyo makes relatively good sounding AVRs, so if you’re happy I’d recommend just enjoying what you have and give your wallet a rest.  If you do get the upgrade bug in the future, and given you’re mainly a HT guy, I agree with others that Anthem should be at the top of your list.  

BTW, you didn’t mention a subwoofer.  If you don’t have one, that should be your next purchase without a doubt.  SVS makes very good and reasonably priced subs with excellent customer support and service if you’re in the market.  Hope this helps, and enjoy the new speakers!
Thanks Siox2. I was running  a pair of B&W 683 s2's previously with the current receiver and they seemed to pair well  However these new speakers do seem like I have to turn the volume up more  and seem  a little muffled. I have  run auto microphone calibration as well  I do have a nice subwoofer but am not using it as it would shake the walls too much and I  have  a neighbor I share a common wall with. I'm really going to think about the Acram but does it make sense to step up to the  720? I just want to buy something where I  won't have to upgrade for a while.  Thanks guys.
My advice would be to get the best Marantz AVR you can for $1k. Marantz puts out new models every year, and when they do the old ones go on sale about 40% off. So their $1.5k (or whatever it is) will probably go for $1k new at that point.

It’ll have all the Atmos/DTX and also will have a pretty good digital streamer for streaming music (Tidal, Qobuz, Spotify, etc.) and will sound pretty good for music also.

That’s if $1k is really your budget limit. It is possible to do better if you have more to spend, but at $1k I don’t think it is possible to do better if you want Atmos (which if you are heavy HT, is worthwhile).

I have marantz SR5012 running an Atmos 5.1.2 system in my main HT system. It works great for tv and movies.

Now my main music system costs 3x more than my main HT system (I don’t use the HT for music), but when I started I did.

If you get more seriously into music, you can get a dedicated 2 ch amp or integrated for that later.
Thanks Kren. I will definitely keep my eyes out for that. Thanks everyone for the input.  I've learned a lot!
OP:  Marantz just announced its new line of AVRs this week, so last years models should either be on sale now or soon, if interested.  The new models are denoted SRXX15 (where XX is either 50, 60, 70, 80).  

Last year's models are SRXX14;  previous year SRXX13, etc.

I got an SR5012 just under two years ago.  Marantz really pushes new AVR models out every year.  Usually there isn't much that changes, though I haven't kept up since my purchase and can't speak to specific changes year-to-year.
You purchased speakers that should have a receiver worthy of their quality,  a receiver that is powerful, a receiver that can bring out the best of your speakers. 
In my case I bought the Anthem MRX720 receiver and my speakers (Merlin VSM MME) came alive, sounded clear and awesome. So depending of your taste in sound if its Marantz, Yamaha that suit you.
I had an Arcam AVR400.
My advice is spend the money for the heart of your sound system, if you cant now save for later but buy the right thing
Anthem if you can afford it, Marantz if you can't. Personally, I think Marantz has been doing a great job for the last few years in both the mid-price and higher end spaces. My only issue: I get the 'porthole' styling as a nod to earlier - wayyy earlier - models, but there are better styling cues.