Company As Profile Field

Does anyone know what's the best practice to add a new Profile Field like «Company»? I have a store with both private persons and businesses as customers.

I have tried just adding a new field, but then it dosent get listet in the Customer-list, as customers are listet by «First name» and «Last name».
So I was thinking of editing «Last name» to «Company», but that is probably not a good idea either.
If anyone has found a good solution for profile fields for both people and companies any suggestions would be much appreciated.