Ask HN: Building an “event” site / vertical social network

I am an Artist first and then an Entrepreneur. I can do a lot of stuff on Wordpress and some on Drupal, but that's just about it.

I have secured a good domain name for Art Openings and I want to put together a site where gallery owners and Museums could post their own events and openings. At first I might have to see it myself and I am OK with it.

Is there a WP theme that I can use? Premium is fine.

Or a plugin? Premium is fine.

Or Drupal?

Or . . a wiki?

Or maybe I could do a vertical social network using NING or Discourse?

Needs not to be perfect, just needs to validate MVP.

Thank you for any and all suggestions.