I would not play with .co if you want to do Spanish market, because god knows how google takes that Colombian domain. He can take it as generic, but with Spanish language on it idk.
Another thing is it is cctld managed by Colombia. So ask yourself whether the domain - in case you have success - is more in danger in the USA or in Colombia.
Also .co are roughly 2x as expensive, but that does not matter because you have them both.
If you talk to God, you are praying; If God talks to you, you have schizophrenia.