PrimaLuna Preamp Upgrade Question

I'm a Primaluna Dialogue line user.  I have the integrated model. 

I think it would likely be an upgrade to go separates all around. But tablejockey is very right in his words of caution/disclaimer.  

One thing that I would personally consider if I was doing what you are looking to do is listen to preamps with 6SN7 tubes.  Primaluna is married to the 12AU7.  They are a good tube, but I do like the 6SN7 sonic signature more.  Some folks think the 6SN7 is the most linear small signal triode around.  I do think it sounds a bit more at ease than its smaller cousin the 12AU7.  It may be more prone to microphonics though--I'm not sure.

Take a look at this preamp-- http://www.dsachsconsulting.com/custom%20line%20stage.html

I haven't heard the EVO line yet.  I would think PL would engineer these to sound better when using its separates--otherwise why spend more for another box? I'm generalizing and giving PL the benefit of the doubt as they have a decent record of providing quality at pricepoints. 

I have the dialogue Premium HP integrated, and what I did was to buy 2 Evo 300 poweramps and run them  as mono amps with a Herron Audio VTSP-2 preamp which is the best of both worlds. And the Primaluna integrated I put into my office system.
So if I was in your situation I would get  2 PL Evo400 power amps and run them as mono amps along with the preamp of your choice and sell the Evo400 integrated

J-Wall. 
No need to upgrade your integrated. Primaluna gear has treated me well. I run a Dialogue HP integrated (Tung-Sol KT150's) with Focal speakers and get great results. I'll parrot what some others here say, and add my 2 cents. Speaker placement is crucial for the Aria line. Mine are 3'+from the sidewalls and 2.5'+ from the rear walls. Treated room, ceiling clouds, corner bass traps, and rear diffusion/absorbtion. I started with Aria 926's but now run the larger 948's.
 Instead of switching to separates, I'd suggest a stereo subwoofer upgrade. As good as the Focals are, they don't dig real deep. I went with a pair of REL SHO S3's, but but you could get out cheaper with SVS, HSU or similar. You've got top shelf gear, no need to change it. Just augment it to bring out the best in your system. 

https://photos.app.goo.gl/uLsEz21iN238APXE9

@stereo5 
@tablejockey 

Am I operating too close to a wall? I figured 3 feet was appropriate for being 9 feet away from speakers. 

And here is the setup. I would appreciate any and all feedback. The more I can learn the more I'd love to pass on. 

https://photos.app.goo.gl/XhLEwkzaxHqmj7Qc7