First I would like to point out that I am a noob in raspberry, but have experience assembling computers and I am used to linux and command lines. Never solder anything nor own something to solder, but I don't see it as a challenge. I'll try to divide what I want to accomplish with my project in points, so if you have a opinion on something and don't really know about other things just "reply" to that section.
1) I would like to use the raspberry pi b+ + hifiberry digi component to use as a music server in two ways:
a) Connected directly by optical cable to my amp (marantz PM6005) and use the amplifier DAC.
b) Use it as a server to play music in a Sonos airplay device
2) I would like to use a usb hub to power the RPi and the harddrive with my music library, and with this having just a power adapter, options for the hub (http://elinux.org/RPi_Powered_USB_Hubs):
a) Belkin 4 Port Ultra Slim Series Hub (Powers the pi quite well, 4.85V across TP1&2 during idle and load. The PSU for the hub is a 2.5A 5v made in china. Seems solid. Does backfeed the mini USB port)
http://www.amazon.co.uk/dp/B0061RSACG/r ... 9NU2&psc=1
b) D-Link DUB-H4/B USB 2.0 4-Port Hub
(Charging port doesn't power Raspberry Pi) What does this mean? It says verified that it works
http://www.amazon.co.uk/dp/B00006B7DA/r ... 4CZ59QNNPF
c )D-Link DUB-H7 7 - Port USB 2.0 Hub External
(Power USB slots can be used to power Raspberry Pi) Does this mean only the ones for charging should
be used?
http://www.amazon.co.uk/dp/B0002AFZVM/r ... 83AF1KRMMO
3) I would like to connect by wifi and for that I have a D-link DWA-127 http://www.dlink.com/uk/en/home-solutio ... sb-adapter
In here (http://elinux.org/RPi_USB_Wi-Fi_Adapters) it does state if it works or not, if someone knows if it will work I would appreciate.
4) I would like a shutdown button and was thinking on this one
(http://www.mausberrycircuits.com/produc ... own-switch) the problem is that it uses the same connection (don't know if the same pins) as the hifiberry, is there any solution for this? How can I have both things?
5) I would like a monitor, as the only one I own is actually a tv, and so it's not nice for programming and such, I was thinking in this
a) http://www.adafruit.com/products/2232 but it's currently unavailable, is there other alternatives? Using the HDMI?
b) if it is easy I could live with something like this http://www.ebay.co.uk/itm/4-3-TFT-LCD-C ... 19e9bb2ca2
6) The software the pros and cons for this project for:
a) Volumio
b) mopidy
c) runeaudio
7) A suggestion for project box is appreciated

Thank you for your time!