Amazon scultps are not the best. For naked warrior woman Obelisk models has some beautifull ones, but the models I bought some years ago are amazons, so I am going to use them. When I ran out my amazons then I would consider buy obelisk for sure!
Being slaves for different parts of the old world, could be ogres (good point), amazons, very tall girls for tribes from Naggaroth... all can happens.
About the unit, my first approach is "the unit represent infantry for a dark elf army" so the stats should be spearmen 3 / 3 / 5+ 60pts.
If I need to go further in detail for a campaign game or scenario, I really like the concept "fear makes them fanatic". Also I would remove the armour because fanatic option do not usually have armour and also do not fit armour in the concept of slaves. (-15 pts)
At last as being a unit of non profesional soldiers could be treat as conscripts -1 attack -10pts
herd of slaves 2 / 3 / 0 special fanatic 35 pts