Well, before I was into Japan, I was into China, but since I was young, the whole concept of their language was kind of hard for me to get to.
However, I found out that Japanese is much easier for me. ^^ I tried taking up Chinese once more last year, and PHALED. xD So I'm just sticking with Japanese.
However, these people here are giving sound advice, and everyone's case IS different, so I say consider both and hopefully you can make a decision soon.