Need a 'Yahoo Answers' Solution For Wordpress Blog

We require advice on choosing, configuring and installing a plugin that will provide similar functionality to something like Yahoo Answers. E.g. https://answers.yahoo.com/question/index?qid=20080517200410AA11bIU - Question / Topic is shown at the top - Other users (including ourselves) can then answer the question / topic - Question / Topic will have its own page/post and be SEO Friendly (i.e. question is in page title and H1 tag, SEO friendly URL) - Users can easily signup and leave a comment (we dont want this to be easy to spam and can moderate ourselves, but at the same time, we dont want a large barrier to people contributing to our forum / Q&A website) Ideally this should be an already available Wordpress plugin that we can configure for our website. We ideally do not want to build from scratch and thus go through lengthy QA / dev and design costs. The topic of the website should be irrelevant to your proposal. We want something simple that we can easily customise.