After some fairly extensive research, read tech specs for the DX79SI and then got in contact with intel tech support. Looks like the DX79SI is out. It can't be confirmed that it will boot from PCIe.
There are plenty of motherboards that will boot from PCIe just look at OCZ -Mobo guide
I am currently looking at the Asus Rampage IV Extreme/BF3. It has all the current set of requirements. Socket 2011, support for the new 3rd gen i7 processors. 8 memory slots supporting up to 64GB of memory. Supports boot from PCIe on bios rev 1101.
It is mid-range in cost, when looking at this end of the motherboard spectrum, the cheapest socket 2011 board is about NZ$300, the Asus is NZ$550 with the most expensive at NZ$850. It is also the cheapest to meet all the specs that I have.
It is a little annoying that the Intel board didn't support boot from PCIe, as it is NZ$390 and meets all the other specs. I may keep it in mind as the hardware RAID controller supports raid 5. And an array of 5 120GB SSD's would give twice the storage capacity, similar performance, though slower in IOPS then the revo drive for very similar money.
240GB revo drive at 200k IOPS @ max 1500MB/s read & 1225MB/s write. NZ$953
5x120GB OCZ Agility III drives 20k IOPS each @ max 525MB/s read & 500MB/s write. NZ$1025.
Because of the RAID overhead the SSD's would give 480GB storage, probably around 60k IOPS and a sustained throughput very similar to the revo drive maybe even faster.
The question is, is it worth the hassle of setting up RAID and making sure it always works, or spending slightly more (more expensive MB reqd) and getting lower storage latency????