I'll spit out one for sure.
There's a concept presented by an ex-air force guy to develop a three stage launcher that seems very practical to me.
The primary vehicle is similar to the Shuttle, but with standard turbojets and one rocket engine. It launches on the turbojets like a regular aircraft (stage 1), but with virtually empty fuel tanks. Climbs to altitude and hits a tanker just like an F-15. Then cranks up the kerosene/LOX rocket engine (stage 2), and accelerates to around Mach 10 and 75 miles. At that altitude, it opens its shuttle like doors, and kicks out an upper stage of some kind (stage 3).
Such a vehicle should be able to launch every day, between scheduled maintenance. The launch profile includes flying under turbojet power a thousand miles or so before the speed run to suborbit.
It seems to me to be a very practical system, virtually identical to everyday military operation, done with off-the-shelf technology.
LETS BUILD IT!
You may be thinking of Black Horse by Mitchell Burnside Clapp. Also see this
There have been numerous horizontal-take-off concepts. Most are duds. Some (like NASP) fail because the materials do not yet exist to make them feasible. My one-size-fits-all comment on NASP-like vehicles: "Every ten years we dust them off and study them all over again. Every ten years we find that the materials are not there, but 'might' be in ten years...so back on the shelf until another ten years goes by."
The altitude and velocity you can get by "climbing to altitude" are negligible fractions of what you need. And being refueled in flight imposes some monstrous problems. I'll mention one: if you are optimized for Mach 8-10, you will have an SOB of a time flying formation with a KC-135 at 400 knots.
Also you will find that ram/scram engines that can work at the kinds of mach numbers required are very rare (there aren't any), and will require (guess what?) billions of $$$ of high-risk, high-payoff research...just like, um, X33 for example.
In other words, the technology you claim we "have"...we don't have, except on paper and in wet dreams. A minimum of 10 years to develop the technology to the point where hardware exists and you can find somebody silly enough to plant his butt in the pilot's seat. And Congress doesn't like expensive 10-year programs; they tend to cancel/redirect/export/ignore them to death.
--Boris