ORIGINAL: DanPeoples
The P-51 sound cool, but if you want to go faster than the P-51 and still be able to land at a slow speed just mount that .21 on the back of a Kavan Projeti. Who sells that .21 I may want one for myself.
You can do a search for Novarossi and you will find a lot of places with them... the trick is to find the ones for airplanes. Novarossi is more well known for the boat and car jobs but they do sell airplane engines too.... one place you may try is
http://planethobby.com