I don't think it is a good shout at all.. Change the absolutly bloody awesome LG to your petty Acer, and what is the price difference???
Mine would come in at £2140 with the acer...compared to your £2099
You seriously would not go for x99 for £40 more? Bonkers.
I know an extra £200 has gone on the x295, but the real steals are the 290's! Not 290s's, nor x295... which he might have throttling problems with anyway.
Two 290's run the LG great, its not like its 4k or anything.
Op's choice of course.
Edit: But dude, come on, you are spending 2.5 k here, you want something special! Think special my friend... There is no reason to not go x99 now, it is a couple of hundred extra that can we tweaked out with budgeting other things a weeny bit.
Oh, did I mention how awesome the monitor is?