Stephen Lewin wrote, "I really do not want to purchase lumber,
stack it, and let it air dry for 6 to 12 months before I can use it."

As I mentioned, I have not built organ pipes; but I have built a fair
lot of furniture.  Here in Germany, when you buy pre-planed pine boards,
they are reasonably dried for furniture use (not air-dried, but
kiln-dried).  Some percentage of it will split or bend, but when you
select the boards with a straight grain pattern and few (or no) knots,
the chance of warping is quite small.

Usually, these furniture grade boards are now sealed in PVC so that
their moisture content does not change after factory drying.  Thus,
they must be stored in the open for some time before being used, so
that they reach the "natural moisture level" for the target area.  Then
you can select the boards.

It is okay to plane down bent boards if you build for relatively
stationary use.  If you want to pull your organ around from the Oregon
coast's damp forests to New Mexico's deserts, then you should only
select boards which remained truly flat, and probably you should use
some other wood which is not going to split as easily as pine).

If you want to go with wood from lumber mills (which you would have to
plane yourself), then you might want to call all the lumber mills near
you (or not so near you) and ask them how long they dry wood before
selling it.  Maybe you find a specialist who dries to furniture grade,
but I would doubt this -- air-drying of lumber is simply too expensive
today except for special purposes, so the woodworkers who need that
must do it themselves.

You should also be able to find input on the rec.woodworking newsgroup
on where to get various sorts of lumber and what to do about drying it.

Regards

Harald M. Mueller
Grafing bei Muenchen
Germany
http://www.haraldmmueller.de/