Hey there... I don't post here much .. more of a lurker .... I do run one of my Klipsch set ups off of Crown power though.
My garage/wrenching on the bikes system .... is: iPod>Mackie mixer($100)>Crown Marco-tech 600($300 used)> Klipsch KP-201($300 used) will absolutely raise the roof and *beep* the neighbors off when idiling along at half volume.
Yes there is fan noise ... if you feel comfortable going used ... look for a Crown K1 or K2 as they are convection cooled and have no fan ... no longer in production though. I would say indoors the Macro-tech fan would be too loud ... in my garage... the volume is generally turned up, so I do not hear it too much.