you are looking at E-ATX/SSI-EEB motherboards so bear that in mind you'll need a big case, a beefy power supply (750W or bigger), and willing to spend some bucks because your list of boards don't come cheap.
On the other hand if you can be on the look out for an
Z9PA-D8 - Overview you'll have a compact motherboard in a tight lil ATX package. Downside? Price of
course. Dual PCI Express x16 3.0 are rare on motherboards with these CPU's, which of course pumps up the price.
The one thing I wouldn't worry too much about is USB 3.0 and Audio (I know you don't mention it). I bought a USB PCI Express card, front bay expander, and front mount kit for $25. An Audigy card cost me $25. The Xeons are designed for high end workstations or servers, USB and Audio are not always found on these boards and if they are they are lousy. If you can give up those 2 (IPMI is also overkill for a workstation great on server) then the amount of boards you are looking for opens up drastically.