Hi,
Appears you are a bit confusing about Heroku.
Is is not a Rails IDE, like Aptana RR or Netbeans.
It is an easy to use interactive deploy and server environment which
in the beginning include an online app editor.
My advice is: try a few more IDEs and choose the one you feel more
comfortable with.
I use Netbeans or Komodo Edit, depending on the situation needs.
Komodo Edit is a lightweight one and Netbeans is a powerful one.
All the best.