I don't know exactly what your requirements are.
Dual monitor capability, also outputs for DVI+HDMI+VGA are all available on AMD's recent release boards involving the 700-series southbridges. Namely the SB700 or most recently the SB750.
The latest boards (SB750) are better performance and power handling.
See 790-GX northbridge with SB750 southbridge. These boards are new releases - most major mobo makers are making them. Also, besides the onboard video, there are available 2 PCIe x16 slots (electrix x8,x8). That would mean you would have additional video card monitor outputs, esp with new ati cards which include HDMI, DVI, and some are dual DVI - depends on maker.
The 790GX /SB750 boards are like the heavy duty, adult version of the 780G /SB700 boards. If you are using lots of power, stay out of 780G's and go with 790GX boards. 790GX will handle 140 watt cpu's whereas the 780G's were for smaller power req's up to 90 watts. (pvm/mosfets)
In either case, the southbridge chips provide the various multimedia functions, incl. HDMI and multi monitor, etc.
There is also a new hi-performance board 790FX /SB750 chip with no onboard video - but it offers multiple PCIe x16 slots. That would handle vidcards and your raid controller methinks.
But you should check specs on these to see if your req's are met. I just know they do multi monitor. I don't know about multi input source for multi monitor. And don't know if that's what you want. So read specs.
Hope this helps.