Champion makes a generator in that size class. I have one and its pretty quiet for a cheap generator! I now have the little 3500w version and no longer use the 5500watt version. If your near Augusta, Ga. I will sell it if your interested.
i got a 5000 watt kingcraft for $400 brand new. runs great! i saw some 5000 and 6000 watt gennys at menards last tiome i was there on sale for $400 brand new. they wernt brand name but if its like mine theyll do the job! one was the same brand as the link above.