You can output that resolution with just about any IGP and simply use a DVI>HDMI dongle or lead.
What are you outputting the sound to? You have four options really: S/PDIF over HDMI where you get 2 channel LPCM or DTS/AC3, 7.1 LPCM at limited resolutions, full 7.1 LPCM, and full bitstreaming.
If you're just doing this to a TV rather than an HDMI amp then you don't need to go to any lengths.
Going straight into my Pioneer amp which is in turn outputting the picture to my Kuro.
Does anything do full bitstreaming over hdmi yet ?
I'll be looking to pair it with a onkyo amp