Best motherboard for specific requirements

[Dredgy]

Hi, I have a very restrictive list of requirements for my motherboard, which limits my choices to just a few.

The main problem I'm having is finding somewhere with enough room for expansion slots, this was mentioned in the review for the Asrock X79 Extreme9, my original choice.

My requirements are as follows:
- 8xRAM slots.
- At least 2x USB 3.0 Headers on board
- Enough space for 2x 2 slot PCI-E gfx cards in SLI
- Enough space for two more PCI-E expansion cards - a HDTV tuner, and an additional USB 3.0 header card. If the motherboard has 3 or more USB 3.0 headers, I won't need the header card.
- RAID support (pretty much a given).

Budget about $500.

Thank you very much

 

[Danbuscus25]

http://pcpartpicker.com/parts/motherboard/#N=8,12&T=65536,131072&h=4,7&u=1&sort=a0 here is a list of mobos that meet those requirments

 

[Dredgy]

I've looked at those, but I'm not sure if some will meet those requirements. Namely the requirements about needing 2x Dual Slot Graphics Cards AND room (physical space, not number of slots) for 2 more PCI-E expansion cards. From the reviews I've read of the Asrock Extreme9 - It won't fit my requirements, and I can't tell with the others since I haven't worked with them.