I agree that speciialunits add more aspects to the game and that you need at least a D12 to make it work. Here is the units that we use in our D12 version:
British:
Commandos
Cost:2,2
Special: May perform perform sabotage (IC)
Ghurkas
Cost:3,2
Special: Stronger Att/Def in Jungle/forest
France:
Foreign Legion
Cost: 3,2
Special: Stronger Att/Def in Desert/ Forest
Germany:
Gebirgsjäger(Mtn-troops)
cost: 3,2
Special: Stronger Att/Def in Mountains
SS-Units
Cost: Pzr-Grenadiers 4,4,SS-Panzers (As the tank you wish to build, Light med,heavy )+4
Special: Enhanced combat values, limited numbers
Karl Mörser
Cost: 7,7,7
Special: Awesome firepower, limited to 2 pieces in a game
Italy
Bersaglieri (Mtn-Troops)
cost: 3,2
Special: Stronger Att/Def in Mountains
Japan
Marines
Cost:3,2
Special: High amphibieous assault value
Imperial Guards
Cost: 4,4
Special: Enhanced combat values, limited numbers
Soviet
Guards/Armored Guards
Cost: Guards: convert inf for 2,2, Arm Guards (As the tank you wish to build, Light med,heavy )+4
Special: Enhanced combat values, limited numbers
Siberian Rifle Troops
Cost:3,2
Special: Enhanced combat values in Winter and Mountains
USA:
Marines:
Cost:3,2
Special: High amphibieous assault value