there are lot of good copywriters around, try to check the 247onlineassistant website. they have been helping a lot who has the same need as yours.
I'll also jump on the Elance bandwagon. There are quality writers on there---the key to remember is that many writers on there are specifically writers: not marketers, SEO experts, or mega-affiliates. You have to be VERY specific with what you want. Length, keyword density, title construction, etc...