I want help in Wordpress site needs addons and configuration

For months I have been attempting to have my ecommerce site built to my needs, however keep running into snags with contractors either promising results they can't produce or merely not being available to meet a deadline. Therefore, here I am one last time

Therefore I am a sound designer and sample librarian. I am attempting to set up my newest site on Wordpress as well as I have little knowledge of the platform from a programming standpoint. Essentially, I am looking for this site to have almost identical functionality as where my customers can preview (audio player plugin installed) and pay for sounds via a credits they add to their accounts(CMS?) using a credits system(plugin installed also). Not sure what else I need however I am willing to purchase whatever plugins needed to get this up and running, ASAP.

Attached are the .PSD as well as screenshot examples of what I need for this site. Let me know the price as well as how long it will take to implement it.

Desired Skills are MySQL Administration, CSS, HTML, PHP, WordPress