You can find some rating sites that cover ORM sites, the companies listed are usually paying to be listed, and where they are listed - i.e. from being listed #1 as the top ranked, best company that mentioned in the article, to the last listed #10 ranked of the list ( if it's a list of top 10 reputation companies, for instance" - depends on how much they pay. With of course the companies paying the websites publishing the articles, or the journalists writing the articles, ranking at the top of the list of best companies, and the companies paying the least to be mentioned in the articles of top firms in any given industry/category, ranking toward the bottom of companies/services/products mentioned.
Nonetheless below are a few articles and sites you may want to look over if you're seeking to hire a reputation management company and want to compare the companies prices, reviews, services or whatever.
List to see for reputation management company reviews