Personally, if i was you i would pick Spanish for sure. If you enjoy it you will probably do well. I picked Biology purely because i loved it and everyone was telling me about how much content it had and how difficult it would be. I ended up getting an A*, and really didn't find it difficult at all, purely because i loved the subject. And you can always swap / drop it if you don't like it if your college allows it, just try and make this choice as soon into year 12 as you can. Goodluck and work hard 🙂