If these Built-In Video MoBos come with an HDMI port and good processor (C2Q)/Memory (4GB) like what this comes with, should that be good enough to handle most graphic apps without investing in a separate video card?

#1, it looks like it has a HDMI port in the back, and X4500 can handle 1080p video.
BUT, if the graphic apps that you're talking about are something like AutoCAD, Maya, or even just more-than-casual video editing softwares, a discrete video card is a must.

#1, the x4500 is adequate for most use. But if you need to add another card, there are 2 pci slots (1 is taken by the modem).