Now that you have decided on you projection/coordinate system,
Some basic math with have you up and running ArcSDE
x-y scale = x-y resolution = precision
x-y tolerance
does it fit in 32-bit hardware limitation?
x-offset
y-offset
grid size
some cov2sde, shp2sdeand, aml and csh/ksh-shell scripting
yeah!
puts the "My ArcMap is slow" into historical perspective