monoprice.com for bulk cabling
DO NOT BUY their HDMI cables, they are crap. buy mediabridge from amazon.com, the metal is built into the head of the connector instead of tabbed in at the tip like monoprice cables.
edit:
If you are going for one cabinet also think about cooling the area. That could be something as simple as an open face, vented door, vented door with active circulation, or some even put in dedicated hvac equipment.