I prepared a list of units conversion from DK to SC2 and it seems the models are enough!
Imp (Drone - Summoned)
Firefly (Symbiote - Lair)
Zergling (Goblin - Lair)
Queen (Warlock - Library)
Abomination (Troll - Workshop)
Ultralisk - Pigalisk (Salamander - Training Room)
Hydralisk (Dark elf - Guard Room)
Infestor (Mistress - Torture Room)
Fatty (Bile Demon - Workshop + Food)
Roach (Rogue - Casinò)
Changeling (Skeleton - Prison)
Brutalisk (Dark Knight - Arena)
Hybrid Protoss (Dark Angel - Temple)
Vampire (Kerrigan - Graveyard)
Infested Unit* (Any enemy unit -Converted in Torture/Infestation Room)
Hybrid Zerg (Reaper - Summoned)
The idea is to use SC2 abilities to emulate DK abilities.
For example units will not be tortured but converted in the Infestation Room by special tentacles. And instead of mystress we'll have infestors that likes to help in conversion with their neural parasite.
If you have other ideas you are free to share them, I'm listening