Multiple Monitor Conundrum

Let me preface this with, I realize this isn't common and after a few days of extensive googling I'm not sure anybody has a complete answer... that's posted on the web somewhere.

I'm coming from a GTX1070 that ran 3 monitors in surround + 1 (4 total)

I've already submitted my order for my new DS system which includes a single LC 1080Ti
New monitors will be ordered later, they will be at least 1080P but PC HW/SW will determine what exactly I choose later

Here's where it gets uncommon:
I would like to expand to 6 monitors
My build has been spec'd out for simulation games mostly, especially X-Plane 11
XP11 lags the system when it runs multiple monitors ergo nvidia surround 3=1=good FPS
X-Plane does not benefit from SLI, actually, reportedly gets worse FPS with SLI

Since my order hasn't been processed (as of this moment), I've second guessed my OptionA: which was to pickup 2 Matrox Triplehead2go's (good for 3x2 arrangement) and wonder if I should go for OptionB before they start building the system

Option B: 2x1080Ti not in SLI (LC of course)

As far I can figure, the 2 GPU's would probably give me better refresh rate and resolution options, but just how doable is that? Will Nvidia surround (or other SW?) be able to merge and bezel correct 6 monitors in a 3x2 arrangement across 2 GPU's? I know that if Windows sees it as 1 monitor XP11 will.

Thanks

-- Ryan

Don't remember without looking but I think Matrox limited refresh @ 60hz
And I'll abandon the whole 2 GPU idea if there's no way around SLI - as I understand it the 2nd GPU more or less becomes a 2nd brain with the 1st