Attempting to design a "native" theme

Hello,

I am very excited about the effort to port firefox to the BeOS and I
decided to devote a little time to creating a theme that will help the
application fit in with the interface.  I am curious to know whether I
can call on native widgets (like menulists and scrollbars) to make the
browser feel even more like a native BeOS application.  Who can I get
in contact with for any advice in this direction?

Here is a screenshot:
http://www.alazanto.org/yellowtab/fullscreen-yellowtab.gif

Download what I have so far:
http://www.alazanto.org/yellowtab