any advice for SGI novice?

[What a waste it is to lose one's mind.]

I am currently in the market for a 4D/25 and am trying to decide
exactly how to configure it.  My priorities seem to be a bit different
from most SGI users:  the unit will be used primarily to develop 
hydrodynamic models (in Fortran), which mostly will be run on Crays.
The SGI will be used to execute test jobs and perhaps some of the 
smaller production runs.  So my main interests are adherence to the
Fortran-77 standard and floating-point performance, with graphics as 
a *secondary* consideration.  

I would also like to use the SGI for analysis of the model results.
The final product must be suitable for publication in professional 
journals.  At present I plan to use a version of the NCAR graphics
package available from a third-party vendor.  This mostly generates
simple line drawings: contour plots, vector fields, etc.  A PostScript 
driver can be used to produce hardcopy on an Apple LaserWriter, etc.
Eventually I may replace the NCAR graphics package with a more 
sophisticated graphics program.

The main question is whether to get the 24-bit or 8-bit color
graphics.  The 24-bit color costs extra money, which perhaps could be
better spent on more memory, disk capacity, or whatever.  The hardcopy 
output will be in black and white. I can't afford a color hardcopy 
device, and besides, the journals charge $1000 or more per page
to print color illustrations.  Therefore it is difficult to 
see the need for 256 colors, much less 17 million.  

By getting the 8-bit graphics instead of 24-bit, would I lose anything other
than a lot of superfluous colors?  Fast and flexible graphics manipulations 
on the tube are nice, *but must be reproducible in hardcopy to be of real 
value for my purposes*.      

Thanks in advance for whatever advice you can offer.


Ray Arritt
Dept. of Physics and Astronomy
Univ. of Kansas
arritt at ukanvax.bitnet
arritt at kuhub.cc.ukans.edu