Premium vs free themes

Hello!

I have checked out other threads and not found any answers thus far, so here I am.
I am looking for a theme, low $ premium or maybe even free if it has the following:

Ability to have Google AdSense, etc
E-commerce
Heavy content
One and Two columns
Video etc.

I know I can make changes to how things look with CSS & that plugins will take care of most of the galleries and videos, etc. Okay, so knowing all of that, am i limited with most themes? Should I only check out certain types?
Thanks in advance!