So, I have a solution that works alright for me…
I got a USB 2.0 displaylink adapter that works with the opensource ugl driver. Specifically: http://www.win-star.com/eshop/goods.php?id=90
I use that for one monitor, and the hdmi out for the other monitor.
It doesn’t seem to use an obscene amount of CPU like I noticed with the closed source driver, and actually seems to work acceptably.
However I did have issues getting it to work initially, and needed to make my own xorg.conf … but I now have it working perfectly fine, other than the mouse flickering during animation on the screen, which I suppose can be fixed somehow…