I have used PC speaker amps and car speakers in everything I've built and been thrilled with the results.
As exception my current mame cab (full size original Virtua Fighter cabinet) I actually have the original speakers in it from ~1993, however they are more or less standard automotive grade 5.25 speakers. I had to reverse the polarity on the magnets for the screen, but otherwise stock using a PC 2.1 system. It shakes the windows, primarily due to the giant ported box that the cabinet becomes.
On my current jukebox I am using a Philips 2.1 system that I have been very fond of for the past ~7 years and two Kicker 5.25" speakers. With the pc volume half way and the speaker volume at about 50% you can't carry on a conversation without leaving the room. I haven't tried full blast yet, but as high as I have gone there's been no break up or loss in clarity. I have no doubt that you could not just hear it but make out all the words from 2-3 houses over... the wood cabinet again helps out I'm sure

Anyway, just something to think about; a quality PC speaker set can drive car speakers quite well, you just need to trial an error which ones perform well in this sort of application, as low quality speaker sets have low quality amps in them.