I have been following this thread and haven't been sure what way I would go, but since you made up your mind I will put in my 2 cents {but be careful its probably only worth 1}.
Now as many know I am all about 2.x music systems, I have a 5.2 system for my ht, but I am not a surround sound guy...
Heres what I would do...
$2000, buy another sub, I am not sure what one you have but I would get another....
now with the money left over buy...
this pair of amps
http://www.musicdirect.com/p-161175-outlaw-model-2200-mono-amp-pair-demo.aspx
then buy this
http://www.ebay.com/itm/Emotiva-XSP-1-Gen-1-/231491037310?pt=LH_DefaultDomain_0&hash=item35e5f0e87e
offer him $500, looks good to me...
Then for digital input just get this guy and tuck it in the back and you are done
http://www.amazon.com/Signstek-Coaxial-Converter-Decoder-Analogue/dp/B00FEDHHKE/ref=sr_1_1?ie=UTF8&qid=1424999414&sr=8-1&keywords=muse+dac
That will get you a great, clean, foundation... The outlaw mono blocks are awesome {look in the link in my sig, I have a pair of them powering a 2.2}, the xsp1 will give you great sub control and is a very nice unit also...
I will put that outlaw, xsp1, with another sub against ANY amp/pre/dac combo on the market with a single sub. Its not as easy as it looks to integrate a single sub into a music system, have 2 subs smooths the room response and makes them invisible. I have a bunch of 2.2 systems for a reason, a single sub is just not as nice..
So I hope this helps, if you get an xsp1 with a pair of mono blocks {no cross talk with mono blocks}, and another sub, you will be AMAZED at the music, I am sure a single sub and the parasound stuff will also make you happy, but dollar for dollar the gear I listed will get your more for your money...
One more not, I would have done bookshelfs vs towers, you are crossing to a sub so no need for the big cabs and that extra resonance {plus the cost}...
What sub do you have?
Good luck with what ever you choose, I love seeing people doing music only systems, and yours will be close enough, I have 7 music only systems in my home, lol...