i guess, display port can give only video, not audio. In HDMI, you can get both audio and video. Also intel DH67GD motherboard has HDMI port and you can use it. You need not use a Display port to HDMI converter for this.
Since my experience is limited to using a VGA to DVI-a adapter I hesitated to respond. I feel it would be safer to use a graphics card with a display port than deal with the differing logic of monitors.