The products that do what you seek do exist. They do weigh something.
Generally, whenever this happens, the bike frame is too small. This is not a problem.
Dimension makes a severe angle UP stem that can correct a minor size error. The newer models are now securely welded for high durability.
Tom Ritchey has an adjustable stem that performs a similar job.
For a bigger problem,
Delta makes a 3 inch riser that can correct one or two frame sizes depending if you put a stem on it facing up or down. Ideally, you will use this with a 90mm stem set facing down. This will restore the traditional "7" shape and balance to your bike. If the bike is really a mess, Tom Ritchey's adjustable stem can be used with this stem riser.
Ideal steering does not come into play until the bike actually fits, but here it is.
Put a yardstick onto the front axle. Make it paralell with the head tube. It should point to or touch a handlebar grip (well, from a side view, anyway).
Basically, you should never be sitting with your back hunched or into a "C" shape, and you shouldn't be reaching as to slide off the saddle. Too far upright will make you slouch. At this point, you will catch wind severely, but anything slightly lower works just fine. Too far reached will make a hunching as you overextend. This will put your body's power into the front wheel instead of the rear wheel.
Anywhere near the right measure will have your back straight.
While North Road's and Trekking bars work great (look carefully, and you'll see a forwards grip position that can duck you out of the wind just as well as drop bars), these fare no better than drop bars if your bike is the wrong size. They do have the advantage of locating the shift-brake lever combos into a usable location. Nashbar's ahead for MTB adjustable stem can get these into the right place for you.
With a very compact bike, the handlebars will usually go level with the seat.
However, a longish bike will have the handlebars 1/16" above seat height.
Drops with more drop provide a better combination of comfort and speed.
These are maximum low figures, and you should know that you can sit higher than that without noticably increasing areo resistance.
For performance, confirm your adjustments with a speedometer. You'll be in for a very nice surprise.