Returning to academia after long break with new research topics
I have been in a very similar situation for quite some time. Sadly, I don't think there is a way out, or rather 'back in' - without the right connections. Unlike me, you seem to have at least one connection, the professor you mention.

You have not given any details of that possible project (and how it would be financed). You should be able to talk to that professor and evaluate the chances for a (later) postdoc position from there. Again, this critically depends on his connections.

If you are really passionate for this research topic, I think you should take a shot. 
If you are OK with not being a researcher, an ordinary job would of course be the safer route.