Why do you want a plane that failed?
The M saw very little action and was eventually terminated.  The other M prototype became the first N prototype....
First off, thanks for taking a lighthearted thread WAY too seriously- if ya searched, you'd have found probably at least a dozen threads calling for the hot-rod Jug.  
That having been said....
I'm curious as to your criterium for failure.  It had teething problems (most a/c did), and the entire 47 line was scrubbed in favor of the F4U and F51 by 1948, so I can't really cite the short service length of the aircraft as a "failure" in any means. 
What it certainly DIDN'T fail at was smashing speed records belonging to the P-51.  473mph at alt?  Yes, thank you.  Almost 40 mph faster then the Mustang.  
I also don't see why the M/N comparison is brought up.  They only share the same engine.  Beyond that, they're ENTIRELY different aircraft.   A comparison of the P-39 and the P63 would make about as much sense. 
**Edit** HAIL ZEUS!