"Bounce house" blowers are relatively cheap.  They put out a lot of
CFM volume at pressures up to about 6" water column.  If you need more
pressure, buy a second and supercharge one by feeding the output of one
blower into the second blowers inlet.

Those Ametek-Lamb blowers will make you deaf.  I tried one years ago.
For your needs, it would be okay, except it might poop out when voicing
big pipes in the 16' octave.

Dave Vincent