Student or Learner
When you find a book you have wanted to read, which sentence do you say?
1. This is the book I'm looking for.
2. This is the book I have been looking for.
If you're talking to yourself, you could say #1. However, #2 is more likely in most situations.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.