I need YOUR help to pick a niche.

Here's the deal. I have a few attractive model type women working with me. My plan is to launch a blog / website which will feature them. On this blog, we will have recorded youtube videos, blog posts and live webinars where fans can interact and chat with them.

I will be generating traffic and promoting my blog on the known social channels such facebook, twitter, youtube, etc.

My only problem and challenge is figuring out what the niche or topic should be for this website. Whatever niche I use the models will be providing the content in the form of the live webinars and recorded videos, so the theme must be a topic that any of the models can contribute to easily without requiring hours or months of experience or insight. Also, I want to try to work with a niche or topic that has a large enough audience.

I want to make it a theme / niche that any of the models can be comfortable with on the site, and also where alot of "niche" knowledge isn't required to contribute.

For example, lets say my niche was "world of warcraft". This is a HUGE niche with plenty of dedicated fans, however my models don't know anything about this game because they don't play it, thus they wouldn't be able to contribute relevant content, and the viewers would catch on to this quickly.

I thought about current events, and celebrity gossip, but not sure if that would be a good topic.

Whatever niche / topic I decide to discuss in the blog, I plan on giving away prizes such as gift certificates, etc to some of the viewers. I was also thinking about making the topic some sort of interactive game viewers can play with the model.

Any feedback is GREATLY appreciated.

So again the million dollar question is:
What niche or topic or theme can I use to represent my blog, but will also be flexible enough for my models to contribute and produce content without having to spend hours and months to be an expert at?