I don't like raid 0 personally, because to me reliability of my data is more important than saving a second or few seconds here & there. Depends what you are doing with your PC though.
Why did you order the 2tb - what was your intent? Are you running low on space, looking for speed, or something else?
I'd consider taking the 1gb green, putting it in an enclosure, and using it for external backups, that can be kept separate from the PC.