Unfortunately I wouldn’t recommend using the portfolio template that currently comes with Ambition as it will be removed and possibly replaced with a plugin to handle this better. As Genesis evolves, the code for the Portfolio is becoming outdated, and I’d like to put more focus on the Child theme/design. It would be better to leave the Portfolio out of the theme and use a plugin instead for the demo.
StudioPress has a Portfolio plugin that you could take a look at. I’m not sure if that would work for what you’re trying to do, but it’s worth a try.
At the time when I first started adding them to the themes there weren’t that many that existed, but now there are more than plenty to choose from.