Hello, came across this thread and thought I would put in my two cents. First of all, I have been running my computer sound system off of a RockfordFosgate 400.4 punch power amp for 6 months now. 
The particular PSU I'm using is a Hipro 160w unit. I desoldered the entire 12V rail from the board, and soldered monster cable directly to it (including ground). I'm currently utilizing roughly 48% of the amps total power(180w RMS). 
I've had no issues what-so-ever from this setup, and let me add how sweet this thing sounds  
 
 
Don't be afraid to experiment a little bit, you never know what you will come up with.
Good luck! 
 
 
 
~Pyro