Building site before knowing domain?

Hey all.

I have a problem. I know what i want to do, and what to build and i want to get started on it. My problem is i have no idea what im going to want to use for the site name or domain, and im planning on putting a lot of content on so its going to take a few weeks of my time (Which is why i want to get started on it)

Anyone have any suggestions what i can do to get started? I have a VPS and everything already that i host my other site on and that i plan on hosting this one on.