as noted above there is no correlation between the KX amp your friend has and the new series of Kicker KX amps. At present time, there is not a 11KX###.2 stereo amp that offers similar power to that 04KX550.2 stereo amp. The ZX450.2 is the closest, but as suggested, I would go with a Class-D due to their size and efficiancy. That 04KX and the current line of ZX amps are all Class-A/B. A Class-D amps can be as much as 60% more efficiant. This means its drawing far less battery amp/hours as the Class-A/B, while producing the same wattage to the speaker. if its in your budget, there are clear advantages to going with a Class-D amp like the IX-500.4. But, if you are trying keep the budget on the low side, then its hard to pass on a $50 amp thats going to deliver 200W rms. Or, go with the new Class-D KX400.4 or KXM400.4 (when it rolls out soon) and run it as a 2 chnl amp and get the same 200W.
Originally Posted by wakeboy