I have been looking for the same thing. I am trying to find a new home for the .46ax in my LT40. As far as Extras go:

http://www2.towerhobbies.com/cgi-bin...?&I=LXGPL7&P=0

The World Models .30 size has similar dimensions to the .40s, so I think that it would work.

http://www.airborne-models.com/html/...p?ProductID=32

And http://www.kyoshoamerica.com/airplanes/gp/11071B.asp.

I wish Great Planes had an ARF version of their extra 300 kit.