Dunno about VT-d support on Z97, traditionally intel usually skimps on that on the overclocking chipset. But as I said, I really don't know, I got a C226 board (ASrock Rack C226WS+).
Stumbled on this review, ASUS Z97-Pro Gamer Motherboard, its a bit on the expensive side at $169, but looks like a solid board. Maybe there is a deal somewhere.
Sounds good if it is officially supported and not just something that might work if you're lucky/mb maker happens to implement it. I've been burned on it before, part the reason I got the Asrock Rack board.
MSI Z97-G45. The Killer NIC is supported in the kernel past 3.10 through the Qualcomm / Atheros Ethernet drivers, and I don't remember having any issues with the sound (though, since none of them on the back are colored in a sensical way, green goes pink port, and mic connection is between that and the PCB). It probably has VT-d (I could tell you definitely as soon as I get a CPU that supports it). It's right in your price range.
Yeah with Sandy and ivybridge this was indeed an issue, since unlocked chips and Z77 boards did most of the time not support it. And unfortunatly i´m affraid the same thing is going to count for skylake again.
yeah well according to some articles that shown some new Z170 boards, they claim that there will also H170 and Q170 boards. On the previous series Qseries board especialy had the full virtualization support feutures. So if they going to make Q series boards again, then it COULD be, that the unlocked enthusiast i7's / i5's might be lacking on vt-d.