The Basso and the Bloat are DAC/Amps so they will bypass your current card via USB from a PC - this may be better or worse than your current card, I don't know, as I've no experience with those products, or your card(s).
Also, if you wanted to use those with a portable player, you can, but will need a line out dock to connect, but the DAC would not be enabled, only the amp.
The Voyager is the only standalone amp there. Slee has a solid reputation, but charges for it
If you don't want to disturb others, you'll probably want closed phones, as open will leak sound.