As has already been said, yes, the DAC and AMP are two separate things. I shouldn't have written "AMP" but "amp".
"Amp" is the short form of "Amplifier". In a nutshell, it amplifies signals.
Yes, there are many units that contain both a DAC and an amp. The FiiO E07k is indeed one of such product; there's also the E17 that has a better amp than the E07k. It is more expensive though. Depending on what you use it with you might hear noise. Usually only the case with high sensitivity IEMs (in ear monitors). Both of them can take S/PDIF inputs (digital coaxial or optical). These two are pretty strictly headphone amps so you wouldn't be using them to power speakers.
**EDIT**
Right. Most modern sources (music player, etc.) have both DAC and amps in them. The quality is, however, generally not as good as in dedicated amps you see talking about on Head-Fi. What Billson says about DACs not working for smartphones and the likes is true for something like the E07k and the E17. These two have DACs you can use with USB (computer) and coaxial/optical sources.You can still use the amp section though.
Depending on what music player you are using as portable, you may be able to bypass the player's amp (volume control). Apple products for example you can use LOD's.