While I have a very similar same setup using the ud3h and am extremely pleased with it, I have to suggest the extreme4. While it doesn't have the ability to have 3 graphics cards installed, no board in that price range can really do that effectively anyway. Yeah the ud3h has a few more usb3.0 ports on the rear panel and has a little mSATA card slot, but usb3.0 is just now starting to catch on, and I doubt that you'll ever need more than the potential 6 ports the extreme4 gives you. And while I was kind of excited about the mSATA slot, I've found that you get more gigabytes/dollar by going with a regular SSD instead of a mini SSD.
But if you do go with the ud3h, I have to say that it worked out great. My hyper 212 evo sits nicely and just barely clears the memory, but I assure you it does. Another nice feature that the ud3h has is the dual bios feature just in case something really unfortunate happens and leaves the first one corrupted. And I guess the additional SATA cables makes for a little incentive as well. I am a little disappointed that it has just one CPU fan, which makes setting up push/pull on my 212 evo a little difficult. I'm not going for record clocks though, so push is just fine for me.
I guess in the end, you'll be happy with either board. The ud3h gives you a little more, but you have to decide if you'll actually use that extra. Not sure if the Xigmatek dark knight is worth the extra $, but it could be. Hope this helps
Tom's did a great roundup of a bunch of boards for less than $160. Check it out for more info.
http://www.tomshardware.com/reviews/z77-express-ivy-bridge-benchmark,3254.html
But apparently it doesn't include the ud3h. Use this link for more info on that board
http://www.tomshardware.com/reviews/z77-extreme6-z77a-gd65-z77h2-a2x,3187-10.html