Emil, it isn't press releases you want if you expect them to be very 'selling' orientated.
Press releases are not sales pitches, they are informative, factual statements that have the additional benefit of exposure for the company it is about.
You can find a good writer at this freelance website. I hired a writer there last year to write a press release for me. I can give you his member id there if you want, so that you can invite him to bid on your project.