Hi Chris,
Just saw your post. The Fox 0.49 glowheads can be had from Doug Martin. They are very reasonable in price, $4 to $5 from what I can recall. Doug's email address is dougsengines@hotmail.com. He also supplies the engines, in I think single and dual bypass format. The dual (?) port is pretty high performance and needs some skill to run well. It is intended for FAI competition in some form or other. The less potent version is probably the best one to have for general flying.
Doug does produce both versions with or without fuel tank. I THINK that the ones without fuel tank are around $69 again if my memory is correct. As Tim Wescott kindly reminded me, "Mattes engine reworks" provide a brass adapter ring for the Fox 0.49 and this takes any of the Cox style heads, for example the Merlin adapters and plug also the Galbreath head and Nelson plugs, as well as Cox heads. Although at the price that Doug charges for the Fox heads, the economics are even and depends on performance in the field! Sorry but I have not done the tests!
If you do not want a tank, but require a radial mount, then I THINK that Larry Driskill at "Kitting it Together" can supply a radial mount. If I have got this wrong, then I am sure that someone will correct me! Suffice to say a radial mount is available somewhere!
Best Regards,
Andrew.