That's 26w rms Len, and I think even that is being optimistic. If you look at all of the headunits out there claiming 4x50 or even 4x60w, it's always meaningless peak power. More like 15 - 18w rms per channel in reality.
The sony xplod range tend to have a reputation of putting style over content. If you link to the speakers you're thinking of, maybe somebody could recommend alternatives in the same price bracket.
Some of the older sony stuff (particularly headunits) are legendary, but I've not heard any of the current stuff get good press at all.
As for amping speakers - yes, components will sound much better running from an amp. Not just volume, but also sound quality.
