UPGRADE TIME!! Preamp vs. Speakers???

Good day audio nutz!
this could be in Speakers OR preamps category but dont know how to post in both..?

I have one I would like your opinions in cracking...
I am considering upgrading either the speakers from Focal ARIA 948 to the new SOPRA n2 (after a demo) OR
upgrading my Simaudio preamp from 350p to the 740P.
The 2 Sim 400m monoblocs and W4S dac DSD SE  would remain.

My questions:
1. What would be the best "bang for buck"?
2. witch option do YOU think would be most noticeable?

I REALLY LOVE the Sim/ Focal sound so I want to stay in those brands I just want MORE of it..
things to consider I get about a 10% discount on gear
the speakers I would get full trade in cost of $5K
The 350P preamp I would get "most" back in the trade up program (plus 10% discount)

Ok let me have it!
and Thank you!
some more great points you all make!

I already have the components and "sound signature" I like.

New plans due to professional room/ acoustics analysis:
Due to my listening area having "not even the basics for great imaging" poor layout of walls and ceilings, small size, unable to move system to another location.

All I can really do is change how I aim the speakers, and move the acoustic panels around. I would not benefit by spending allot more on the stereo itself w/o addressing the other problems first.

Stringreen:I already have "overkill in components for what I have to work with"
I will not be selling my equipment as I do not want to loose anymore money in trade or whAtever other direction I go.

I’m using a Simaudio 740i Integrated amplifier with a new pair of Sopra 2 speakers. Previously I had a pair of Focal 1028be2 speakers also using the 740i.
The Simaudio electronics has a very musical smooth sound that matches quite well with Focal Speakers. I’ve heard both models of the Focal speakers using Macintosh, Spectral, Hegal and Naim electronics in addition to my own personal Simaudio 740i amplifier. I think the Macintosh and Simaudio gear is the best match with the Focal sound.
The Macintosh (solid state) seemed a bit more "colored", especially in the bass....the Simaudio was a bit more neutral but both were very musical sounding on the Focal’s.  I could live with either amp but given the choice I'd go with Simaudio.  Haven't heard tubes with either model of the Focal I have owned, but I'd sure like to try some Audio Research Reference gear with the Sopra's.