I know that an AMD APU can combine with Radeon dedicated graphics cards and be even more powerful, can an APU combine with ANY Radeon card? http://www.newegg.com/Product/ComboBundleDetails.aspx?ItemList=Combo.2492000 My friend is thinking about getting this build and putting something like a 270X or a 280X or a 380 in it, would that work?