Those you linked might work but are not really the right kind of thing. They are designed to take a line in signal and buffer it to drive low-impedance headphones. They don't necessarily increase the signal voltage, but they provide power gain by increasing the available current.
What you need is voltage gain, you don't really need power gain at all. A simple op-amp circuit could do that with around 6 components for stereo, or you could use an audio transformer which has the advantage of not needing any external power.