[Professional Engineer]

I'll take an airbreathing engined mach 6+ craft...

That'd be quite a feat. Getting the air to subsonic speed before the first stage compressor presents a challenge.

Most the of the plumbing on the underside of this beast was required to do just that.

[Darksheare]

THAT was a sweet aircraft.
(What about a combined cycle engine? Works like a ducted rocket for portions of it's operation, a ramjet for others.)