I have been using a 5503 for a few years to drive some 4 ohm speakers. This amp is a beast, it can drive the speakers to a volume level as high as I care to go without any kind of problem.
I have posted some pics of the insides of the amp in another thread,
http://forums.audioholics.com/forums/showthread.php?t=56545&page=8
note the Coke can sized caps.
Here are some of the specs from the manual:
200 watts continuous average power into 8 ohms at any frequency. 20Hz to 20KHz with all channels drives at less than 0.18% THD
350 watts continuous average power into 4 ohms at any frequency. 20Hz to 20KHz with all channels drives at less than 0.18% THD
Power consumption
quiescent 199VA
200 watts into 8 ohms 855VA
Maximum 1440VA
Make sure to check the shipping costs as it weighs 57 lbs.
If there is nothing wrong with the amp, that is a good price.