What is the right shaft for me when I buy a set of woods? I am 6 feet
tall and I usually drive the ball between 240 and 270 yards. I don't
hit it very high with the driver even with a 10.5 degee. My handicap
is about 10 to 16.

After researching the two websites below you would need standard
length clubs with stiff or regular shafts.  "Stiff" for more distance
and "regular" for less.

http://www.correct-fit.com/swingspeed.html
http://www.bestbuygolfsupply.com/ping-golf-clubs.html

I hope that answers your question....

To determine what shaft you will need, your swing speed should be
recorded.
Most amatuer golfers have a swing speed of between 70-90mph for which
a regular shaft would be recommended, if your swing speed is faster
then a stiffer shaft would be needed.

You mentioned that you dont hit a 10.5 degree driver very high, then a
stiff shaft wont get you anymore height.
Best suggestion is to go along to any pro shop or driving range and
try out various models with loft and shaft variations.  Maybe even try
a 12 degree lofted driver, you wont notice any difference in length.

The decision to go with graphite or metal is also influenced by age
and existing injuries.  The graphite shaft, offering more flex, is
better for slower swing speeds. Men sometimes switch from metal to
graphite as they get older and their swing speed gets slower. 
Graphite also transfers vibration less, which lessens the negative
effect on your body when your clubhead hits the ball. Any injuries
such as a bad back or painful wrist may sway you towards the graphite.
 Lastly, if you travel often with your clubs, that speaks in favor of
metal shafts, as graphite shafts are more fragile.

i would say a stiff steal shaft that has more bend closer to the
clubhead as this should promote a higher ball flight