Hi batigol,
It looks like you're not entirely sure on what a pre-amp is. Basically, a pre-amp takes a signal, and amplifies it. For example, the level of noise that a microphone emits is not enough for the computer to handle it, so the audio interface amplifies that signal before sending it to the computer.
If I am correct,
this is the interface you're looking at. While this interface has 4 inputs, it is 16-bit. I'm not sure if you know what the difference between 16-bit and 24-bit is, so
here's a link. The bottom line is in this time, you would almost always want to have a 24-bit interface.
Now, the audio interface that fits you depends on how much your budget is, and what you'll be recording. If you're just recording guitar, bass and vocals, the
M-Audio Fast Track will be enough. However, if you're recording a full drum kit, it isn't uncommon that you'll need 8+ inputs.
It also depends on what DAW you're using. A lot of interfaces will come with a stripped down version of some software, whether it's Cubase, Pro Tools, or Studio One. Out of these, I'd recommend
Studio One, which comes bundled with the PreSonus Firebox and
Audiobox series, which you can check out
here. The 44VSL goes for about $350 and has 4 inputs and MIDI I/O.
Let me know if there's anything else you'd like to know
