Could someone give me advice on what the best way to get Opera to run with Flash on my Gentoo install on my PowerPC?

I've had a bit of a go and I've found that the mplayer plugin appears to require firefox:

"configure: error: Unable to find mozilla or firefox development files"

The gecko-mediaplayer plugin requires gnome-mplayer unfortunately I'm running openbox with GTK but no Gnome. (I use the basic mplayer.)

Gnash uses gstreamer - which is hardly light weight and in my experience buggy, but this might still be the best way to go.

Any suggestions would be appreciated.