Amp / Speaker combo ~5k

Good stuff you have listed there.  Are you buying new or are you open to used?  Just perusing the listings here, there's a Hegel H160 and Reference 3A Grand Veenas you could get for $4850.  Both look in good shape and would fetch over $12,000 new retail.  Personally I think that's potentially a step up above what you're looking at, assuming they meet your tastes of course.  Just a thought, and best of luck. 

The Sierra towers need the RAAL upgrade, bringing it to ~$2900-$3000. I would say the Sierra’s would image a bit better than the F206’s, and have deeper bass.  
  
The F206’s are also $3500. So unless you are getting a discount on either/both, that would be $6000 with the Halo.  
 
I think spending 50% of your budget on the amp is very wasteful.  
 
I would get an Emotiva PT-100 + XPA- Gen3.

That leaves $3700. 

A similar company to Ascend Acoustics is Philharmonic, and their tower, the Phil 3. It’s better than the Sierra tower, and it has more then enough bass.

There is also the KEF R700 which is also $3000 right now.

Room treatment is also important.

I  had a Parasound Halo for almost 2 years.  It was ok, but not as great sounding as the magazines would have you think.  There was a thinness in the upper mids which I never liked.  I bettered it with a McIntosh MA6600 Integrated which went for 6500.00 new and I purchased mine used from Audio Classics for 3300.00.  It is a night and day difference for the better and I now spend many hours a day listening to it.

Interesting, stereo5. Do you mind sharing what speakers you were using with the Halo? This is a family room system, so I need a flexible, reliable amp with multiple inputs.