Set particular to a point emitter
on frame 0 keyframe particles/sec to 1000 or some high number
on frame 1 Keyframe particles/sec to 0
set velocity random to 0
away you go!!
The spacing of the particles is still random but they will form a good spherical shape now. Trapcode form may get you exact spacing if you need it although my first choice would be to use 3D studio Max.
3D animator and VFX specialist