Im planning to be using Sibelius 7 and Avid Pro tools MP9 as my software, though i havent looked greatly into it. Why does it matter which software I use?
Do NOT get the Xonar, it will not do what you want it to do.
I would recommend the M-Audio Delta 1010LT, but I don't think it provides phantom power. The best option to get the connectivity you are looking for would be to get a separate MIDI interface like the M-Audio MIDISport 2x2 (or the MOTU Micro Express USB if you need more than 2x2 MIDI), and an external audio interface like the MOTU 4pre, or the MOTU UltraLite-mk3 Hybrid. Alternatively, if you don't already have a mixer, you could always get a digital mixer, or a mixer with an audio interface built in (like the Mackie Onyx series) as well.