I am building a new moode player

[remy1961]

I believe that you may want to keep the costs in proportion to the already incurred expenses. Considering that the BOSS DAC requires less than 400 mA and that you are already content to use a SMPS for the RPi why not use a similar solution albeit a widely recommended SMPS manufactured by iFi:

   iFi iPower 5V

Hi,
Thanks for the suggestion. I know that @soundcheck (diyaudio forum) who is a sort of guru when it comes to audio had only nice things to say about the iFi iPower. It is a bit expensive at 69 canadian dollars. The good thing is that I can get it from a local supplier here in Montreal, saving me the shipping cost.
It will definitely be one of the solutions i will consider. 
Remy