So I did more research. This is very new knowledge on the internet so there's not a lot of information to find. A good starting place is this article on TFT Central, updated just a few days ago.
A few monitors support what is called strobing or scanning backlight. This achieves fluid motion with very minimal blur, similar to CRTs. It requires a 3D-vision capable NVIDIA video card. Only a select few monitors support this, and so far the best 27" model seems to be the BenQ XL2702T I was referring to.
There are also some 1440p IPS panels that can be overclocked to 100-140hz, like the QNIX QX2710, which sells for a ridiculously low price (~330$). However, you're dealing with Korean vendors, customs, poor packaging etc. Furthermore these do not support strobing backlight so while the higher refresh rate will provide better fluidity and somewhat reduced motion blur, it will not approach what can be achieved with a strobing backlight. Also, doing 120fps at 1080p is taxing enough on video cards, 1440p is really pushing it. I don't think even SLI'd GTX 760s will be up to the task at high settings in most games, and I don't want to go for 770s or anything more expensive.
So basically I'm trying to decide between a beautiful 1440p panel that's less expensive but shipped from the other side of the world and doesn't support a strobing backlight, or one that does and is shipped from Canada, but is a 1080p TN panel.
I might just get the BenQ for high-speed gaming and think about adding a high-resolution monitor for other purposes later. Decisions, decisions....