since DBP supports only DX 9.0, then you must have latest DirectX 9.0c installed on your machine (even if you have windows 7, and DX10+) and yes, u CAN install both DX9.0c and DX10 on same machine.
no need to include any files of those u mentioned as long the DX9.0c is installed on the machine you runing your game.
if you look into professional installing system E.G InstallShield, you will find that there is an option to include DirectX 9.0c to your installation in case it doesnt exists on machine.
you also can make your own installation systems like step by step before playing your game..
i hope i explained most of the questions of yours