Im currently using Ageis Shield ---- Ageis Deflector --- and borg engines,
I have Maco XII shield but still tring to get the other 2 parts. Drops seem to be poor on them.
The Maco engines and deflector only drop in the khitomer accord and cure space elites, incase you weren't sure.
In the meantime I strongly suggest you use the borg engines and deflector with the assimilated console to get both the healing abilities, and use the Maco shield because it's the best shield in the game. Nothing beats it, especially against the borg. It has a hefty 20% plasma resist and a 10% resist to all damage, plus the 5% bleedthrough instead of the normal 10% of non resilient shields. Also, it has a very high capacity for a resilient shield. Two Aegis mods in my opinion aren't worth the first set bonus that only gives a slight defense boost.