The only company that I can see doing an injected plastic M-50 is Trumpeter. But they would pooch the canopy, get the fin tip wrong, or put afterburners on all four engines (the real thing only had them retrofitted to the inboard units). Annnnd, it would probably cost around $200. But it would be easier to build!
BTW, was your Aurora kit the "nuclear powered bomber"? That was a Holy Grail kit when I was a wee lad. I never did see it in the stores though.