|That's correct. Typically, you might use the hybrid crossfire feature with a $20 HD3450 video card. Cheap solution for older games, but not for modern gaming.|
New games would require a modern high end video card and the hybrid crossfire of the 780G chipset would be wasted.
Read this entire article for an idea of best choices in video card(s)...you'll get an idea of which way to go with the money you have to spend.
Keep in mind a psu with a fat +12v rail (neighborhood of 50a) needed to run high performance video cards can cost 70-120 bucks.
All depends on how much money you want to spend. It's easy to spend $1200-1500 or more on video cards and a suitable power supply. IMO, a real waste of money just to play a game.