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!
I will concur w/ ddafoe-

the pre-amp is the "heart" of any system and one should not skimp/cheap-out on this piece of gear.

It is interesting to read about mating a Simaudio product w/
Pass Labs.
Wolf: that would definatly be THE most COST EFFECTIVE answer..:)

My Dac is capable of acting as a "preamp" w/ vol and balance controls. But my Sim has a definiant sound improvement.

I also like that the 740 has a much finer DB volume control and the cool metal remote, could be used as a weapon if necissary.
Hard to say which of the two will have more impact in your system, but I generally like to start with upgrading the speaker first, because I find it's generally easier to match an amp / preamp to your speaker, than the other way around.

And as others have mentioned, you typically get the most bang-for-buck with the speaker, so might as well pick your ideal speaker, and build the rest of the system around that.
To me it's always the loudspeakers which have the very most impact on what you're hearing, but there are limits as to how much  better you can get.  And with loudspeakers there's always the issue with how compatible they are with your room, where they can sit in the room, what kind of amp you're running and what your budget is.   All of this factors in.

Preamps aren't concerned with room size, what power amp you're running (for the most part), etc.

You mention having a $5000 budget.  In that case, I heartily recommend you seriously consider the Linkwitz LX521 system.  Most do them as a DIY project, which is where you get the very best price, but there are guys out there who will sell you a fully built, plug 'n play setup, at considerably more money than your $5000.  But within your budget, you can build an LX521 set, WITH AMPLIFICATION, and have $1000 left over.  The LX521 is not surpassed by anything at any price.  Build a pair of these things and you'll never buy another loudspeaker, ever.

The other option is that for about $3000, when you can find them and they do pop up here there, is a used set of Linkwitz Orions, which are the LX521 predecessor.  That's what I run and I have yet to have a visitor come to hear them and not leave without envy.  And when you buy 'em used, they're already built...