Hey there @nicksmith – You can’t use any of Structure’s stacks within Foundry. Doing so would be including one framework within another framework, and that would be a bag full of headache.
As for a floated image – Bootstrap doesn’t have a native component for this beyond the Media Group, which @fog1horn mentioned above. I find the Media Group to be a good alternative to using the built-in Float stacks that come with Stacks, if needed. In all honesty I’d not received any other requests for such a feature since this original thread popped up over a year ago. I’ll take another look and see if it is something that needs to be a part of the Foundry suite of stacks though.