Wilson Sasha 1

I 2nd adding your subs. The crossover that JL makes will work well. I would even try them at 60hz. Your speakers are starting to dive there. I added 2 JL E112 subs a few years ago and it stopped my upgrading. I will probably never have a system without subs again. 

I forgot the add the Sasha 1 is one of my favorite all time speakers and I think spending more is silly unless you have a very large room to fill. 

Maybe bor the best or the most accurate but I enjoyed them the most. 

I have the Sasha 2s and love them. I have never heard the Sasha1s but I am sure they are close. IMO it is very difficult but not impossible to add a sub and still have a well integrated sound and might end diluting the factories intended excitement and realism. The improvement in the tweeter, mids and upper bass over the Sophia will not be had by adding a sub. If you are hooked on the Wilson sound as I am, moving up the ladder might be your best bet.

Musicfx,
I still have my Sophia 2s at the moment.   Actually, as james633 suggested, late last year I integrated my two f112s in with my speakers and it has worked really well.   Not perfect by any means, but really close.    The Aye KX-5 Twenty has two sets of XLR outputs and I just ran one set to the subs and set the cross over at 60hz on the subs themselves.   I really like the sound--Not only added a lot in base, but the whole soundstage become so much deeper.

I'm still looking at other speakers and certainly have looked for Sasha 1s on audiogon, but have not really seen any lately.    I've also listened to the new Sasha 2s, Paradigm Personas as well as the Monitor Platinum II.   All have have nice sounds with the correct electronics. 

I've had some other financial responsibilities come up, but I'm still looking to upgrade.   I can't really afford the speakers at the moment, but am looking to upgrade my Schiit Yggdrasil DAC to the Chord DAVE or Ayre QX-5(as I mentioned on your thread).   Also looking to upgrade my Oppo 105 to the OPPO 205 along with a new 4K projector.

Expensive hobby, but you gotta love it!   

Most things in life are a compromise to most people. Remember to enjoy where you are.