The Shadows wouldn't have given the Drakh their best toys any more than the Vorlons handed out anything but the most basic elements of their high-end technology; adaptive armour that took a long time to adapt to any use other than a standard white star and some jump engine improvements.
BUT....given that they've left, there's no reason that the Drakh wouldn't go a-looting before packing up. And we know they salvaged some of the Shadow's hidden arsenals in order to obtain the nano-virus and the planet killer.
I imagine they would have more luck refitting shadowtech to their ships than the EA would...they do have a higher technology base to start with.
Shadowtech raiders would be truly gross if left small, but I can imagine it would be more likely to pop up on a larger vessel. If you want to give the Drakh an Armageddon-priority ship, a cruiser or mothership with Shadow armour and weapon systems seems a good suggestion.
hm...
Shadowtech Drakh Cruiser
Only deployed on the Council's most vital missions, the Shadowtech-enhanced cruisers are as yet few in number; developed by retrofitting armour, drive technologies and weapons from their former master's hidden arsenals onto Drakh ships. These vessels are the most powerful ships the Drakh hace access to, but are - for the moment - irreplacable, so they are not lightly committed to battle, and despite their fighting power, are invariably fielded with a substantial escort.
Drakh - Armageddon Priority
Shadowtech Cruiser
ISD 2268+
Speed 9
Hull 6
Turns 2/45
Damage 60/10
Crew 38/7
Troops 3
Craft -
Traits: Advanced Jump Point, Flight Computer, GEG 3, Self Repairing 2d6, Command +1
Weapons:
Molecular Slicer Beam - 30", 6 AD, F, B, P, SAP, TD
Phasing Pulse Cannon - 8", 6 AD, F, AF, SAP, DD
Phasing Pulse Cannon - 8", 6 AD, P, AF, SAP, DD
Phasing Pulse Cannon - 8", 6 AD, S, AF, SAP, DD
Uses the 'Hyperspace Mastery' special rule when making hyperspace jumps.