Which will I choose between the two?
DirectX 10 and 11 are similar, but not equal. There are very few differences. Windows XP supports up to DX9, Windows Vista and Windows 7 support up to DX11. If you care to read more, see Wikipedia: http://en.wikipedia.org/wiki/DirectX#DirectX_10And about the DirectX, what are the advantages of DirectX 11 over DirectX10?