A workflow question in FCP X

I have a footage taken from 2 cameras and audio recording through an external interface. I have to synchronize the audio with the videos of those two cameras, and select the clip sections I want to use. I created an FCP X project and synchronized all those things altogether. My timeline shows two clip lines (camera 1 on the top, camera 2 on the bottom), audio is properly synchronized, and the clips are full length. From this, I want now to select only a few sequences of these clips for the final editing, but I don't want to loose the layout of the full length clips as it took me time to synchronize those, and I may have to get back to it later to grab more sequences. My problem is I don't know how to do this sequence extraction in a convenient way with FCP X. I thought of creating a third line of clips in the timeline, representing the final editing, and disabling the two other lines. But there doesn't seem to be a way to duplicate clips as arranged in the timeline. Another option I have is to render the initial project (with everything synchronized and full length clips), then create another project and import result of the rendering, then selects only sequences in this rendering. I don't like very much this option as if I need to modify the first project, the second will be impacted too.
What would you guys recommend? Thanks in advance.

well looks like I have the answer to my own question: I had to synchronize the two cams and audio altogether, FCP X then creates a compound clip and from there I can selectively use the blade tool to create portions of clip I can then disable in order to let the each other cam video play. Then I just have to go one step up in the timeline to cut out the sequences I want. Should work, I'll try this.