air abrasive units for fossil preparation

From
Date
The Houston Gem and Mineral Society is in the market for an air abrasive unit
for fossil preparation.  We sure could use some help selecting a unit.  We
understand Swamco and SS White are leading manufacturers of high quality
units.  The Houston Natural History Museum has recently purchased an SS White
rebuilt at the factory for about $2000.  This included a one year factory
warrenty.  I think it is a model K.  We have budgeted up to $2500 for our
unit, so this would definately be a good unit for us.  I  have a dealer
looking for a system, but availability is a problem.  I have also heard of a
model 6500 SS White available reconditioned for about $1100.  Anyone know
what I'm giving up when I go to the less expensive 6500?  It is a less
durable unit or is it limitted in the size blast I can shoot on a fossil?
 The Swamco I heard about is the MV-1.  It costs about $2550 new and was
descibed as comparable to the SS White model K.  I am also familiar with much
less expensive units like the Danville Engineering Micro Etcher (under
$200?).  We want to pursue a more professional quality instrument.  Any
information on the relative merits of these units or availabiility of an SS
White Model K would be appreciated.  
 
If you are in the Houston area and want to get involved in our lab and use it
drop me some email.

Thanks,
 Karl Schleicher
 Treasurer
 Paleo Section 
 Houston Gem and Mineral Society