You may wish to research the world record for height in a balloon.

Also remember the big problem is speed not height.

c/feet/miles/

Also that is only 1/3 of the way up.

You have totally ignored the point I made above that the problem is speed not height.

To keep up with the ISS the balloon would have to fly 20 times as fast as Concorde.  Balloons do not fly that fast - the atmosphere gets in the way.

Items in Low Earth Orbit have a minimum speed of about 7.5 km/s (16 800 mph).  When they drop below that speed they drop out of the sky.  The big problem with launching satellites is not lifting them 100 mile straight up (although that is hard) but accelerating them to nearly 17 thousand miles per hour.  Any launch system has to solve both.

The thread you are looking for is called "magnetic propulsion" and is in the "The Lifter" forum.
http://www.liftport.com/forums/index.php?topic=691.0

Redoing the vehicle calculations when constrained by energy.

Start with a 100 kW electric motor.

Solar panels required
Area of 30% solar arrays @ 1,366 W/m/m is (100,000/1366)*(100/30) = 244 square metre
The solar array can be a square with 15.7 metre sides
Mass of solar cells @ 100 W/kg is 100,000 / 100 = 1,000 kg or 1 metric ton

Estimated mass of car = 2,461 kg + 100 kg + 48 kg + 25 Kg + 1,000 kg + 3,520 kg = 7,154 kg
Rounding this up to 7.2 metric tons.

Time to 60 mph = 26.82 m/s

Using t = (m v²) / (2 P) = (7,200 * 26.82²) / (2 * 100,000) = 25.9 seconds

(The much more powerful motor and larger solar panels are being used to produce similar a similar time.)

Time to 1,000 km/h = 278 m/s

t = (7,200 * 278²) / (2 * 100,000) = 2,782 seconds or 46.4 minutes

The descending flywheels can be used to lower people down the space elevator.

R G Clark the NASA people will not take this idea seriously until they have seen some detailed maths and blue prints.

A mini version can be made by stringing a cable pair from the floor to the roof and running a first stage launcher up it.  The vehicle hangs below the cable.  This can be filmed.  Then move the whole lot outside and hang from a balloon.  The second stage can be made by simply dropping off the cable.  The first stage locomotive parachutes back to the ground for reuse whilst the second stage uses its rocket motor.

Use the rocket equation to show the different amounts of rocket fuel needed for a delta-v of 7800 km/s and 6800 km/s.
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=5933&start=1

We cam have enormous solar panels and cooling radiators at GEO point so 20 times the energy may not be too much of a problem.  They only have to be lifted once.

It is a little harder having motors and solar panels at the counter weight because the mass has to move.  Its negative weight goes down the nearer you get to GEO point.

The cable can be widened using equipment at GEO point as the cable is wound out.  Additions to the above GEO point cable and below GEO point cable will have to be carefully coordinated to keep the weight, lift and breaking strength similar.

The 1000km to 2000km at the very top and bottom of the cable may need special handling.  There is a little alarm bell going off at the back of my mind warning me that winding the cable all up may cause problems.  A means to stop the entire cable spinning around GEO point may be needed.

A climber will be needed to lift mass from the bucket at the bottom to the counter weight.  Since the cable can be in the wound in state at the time this may only be 2000km to 4000km.  The same climber (or pair of climbers) can move cargo from the bucket to GEO point and is reusable.

Some of the solar panels can be light weight mirrors, saving mass and money.

The page on Specific Strength is interesting because it gives the breaking length.
http://en.wikipedia.org/wiki/Specific_strength

Aluminium has a breaking length of 22.65 km and steel 25.93 km. Kevlar's breaking length of 256 km means it may not need tapering.
Graphite may be cheaper and is a reasonable conductor of electricity, breaking length 250 km, but to prevent burning may need coating with a metal like aluminium.

Military fighter aircraft are designed to take accelerations of 10g.  Civilian aircraft about 3g.  NASA throttles back manned rockets to 3g - 4g.

1g = 1 Earth sea level gravity = 9.81 m/s/s

v = u + a t

v² = u² + 2 a s

E = 0.5 m v²

P = E / t

Where

u = initial velocity in m/s (metres per second)
v = finial velocity in m/s
a = acceleration in m/s/s
t = time in s (seconds)
s = distance in m
m = mass in kg (kilograms)
E = energy in J (joules)
P = power in W (= J/s) (w is watts)

Cost matters as well as strength.

Any carbon in the lunar elevator will have to be launched in a rocket from the Earth at thousands of dollars a pound.

Currently no one.

I suspect that there may be significant cost saving from using a hybrid ribbon.  Make the core from Kevlar or M5 launched from Earth.  Surround with strands constructed using raw materials mined on the moon such as fibre glass.  The cross struts would have to allow for differences in expansion.

The 2007 rules banned batteries.

Take care when using the prices on SpaceX's website.  The Falcon_1s will probably end up costing $12 million each with about the same again for launch and management costs.

p.s. Virgin Galactic's Space Ship 2 does not actually go into orbit.

The two craft advertised can be used as 2/3 of a LEO cargo launcher. Two and a half million dollars to lift 100Kg into orbit = $25,000/kg is still expensive.