My JBL/Crown A6000gti does 8000W @ 4 ohms.... well actually right now it's in Tacoma being repaired, but it has and it will again.
OP, Massachusetts craigslist is terrible. Avoid at all costs. There's one guy on there that has some decent equipment, but the prices aren't amazing and it's all pretty high end stuff so may be more than you care to spend.
If you think an amp is worth looking at, use the search function here. Many make rated power, many do not. ANYTHING you'll find local almost without exception will be overpriced.