There is the new Hireme by MSolutions that I use that allows more of a Fiver setup. Nothing 100% just for those two things. Hireme also does not allow a preview of the file, just download for best quality, but could use an app on side like sounds/videos and embed into the post/comment answer (I use froala editor) to show someone the sample. Would be an awesome idea for someone to make something like this though. I am hoping maybe when UNA gets payment module in other modules, maybe developers may implement it, into already created modules like Sounds which I use personally as well. (One thing I am waiting on with the Hireme is for them to find a way to make the messages between the seller and you private. They will post to your timeline when you answer, they are looking into a fix for that though)