Stereo Preamp suggestion


I intend adding a Stereo preamp with HT bypass and subwoofer out to my setup below
KEF R900 mains
KEF R600C Center
KEF T301 surround
Pair of SVS SB3000 Subs
Mains are connected to Parasound A21+ poweramp and the rest is connected to Marantz AVR 7011.
Im looking to get a stereo preamp with HT bypass so as to enhance the music listening experience.
Any thoughts on which brand/model of preamp I could go for considering that I want the subs also to be activated while listening to music. 
I am looking at the following models of Stereo Preamp:
1. Parasound P6
2. Parasound JC2BP
3. Anthem STR 
4. Rotel 1590 MkII

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I have to agree with last two posters. The Parasound P6 is just want you want to integrate 2.1 with 5.x from AVR. I had the P5 and now P7. The subwoofer can work with both.  I use Roon and DSP for 2.1 and anthem avm60 arc for theater. Best of both. 
Parasound P7 is worth consideration here, as many listeners, including me, believe that its sound surpasses that of P5, P6, or HALO integrated’s preamp section. The P7 has only one sub output, but you can use a y-cable to split that output for use with two subwoofers. Since the P7 is discontinued, Parasound cut the price in half, making it a great value too.
Check out the Rogue RP-1. It has two outputs, one you can use for your sub. It also has a really good phono preamp for the price point.
@elliottbnewcombjr 
thank you for the elaborate response. I intend going for the second option of adding a preamp in between the AVR and power amp.
as for subs (sealed ones) location they are adjacent to the L and R mains so that is not a concern as such.
From the posts so far I believe only P6 or Anthem STR would fit the requirement. Unable to decide which one to go for since STR has the ARC which is being raved about.