One problem with the Gropos set was the only troop books put out were Earth, Minbar, and Narn. Everybody I knew wanted Narn on Centauri action, of course. ;->=
I heard nothing but good about the rules, though never tried them myself, but they never seemed to take off.
I think I have a copy of the beta Centauri that the author reputedly shared after the system stopped publishing.
If you end up being interested in going for the B5 instead of just using the rules, I'll look around for the file.
Doug
Edit: Okay, not finding the original file, but did come across a very limit document on the make up of a Centauri company. Anyone else who asks, keep your expectations low. ;->=