Got Foundation? Got NanoFX 2.0 Beta? Install away then.
Any modern mod requires NanoFX at minimum, the rest what you might need is supplied with DS9FX: Submenu, Unified Main Menu, Foundation Extensions, Xtended Foundation Extensions and such...
For any similar future questions: Xtended is designed in such a way that it will operate on any kind of installation (provided that you have installed the mod requirements I mentioned) with maybe some limitations (which are mentioned in the manual). The limitations I'm mentioning are with Galaxy Charts 2.0's War Simulator and Xtended Missions which require you to disable War Sim to be able to play Xtended Missions. There is simply no way to make this work together as both do practically different things with ships and collide.
And final word of advise: If uncertain when to install DS9FX Xtended, just install it as the final mod on top of your BC to be sure.
BTW Guys I'd encourage constructive criticism at BCS-TNG forums (good or bad), things you don't like or liked and would like to see changed with possible suggestions on how you feel it should have been done. I do hope to do a 1.1 version with a new campaign and some new features I couldn't add to 1.0 and feedback will help with Xtended being improved.