The best approach is to set up a unified table of owners. This could be a separate table with links to both the individuals table and the Companies table to record details specific to each. Another option is to combine the data from individuals and companies into a single table leaving empty those fields only needed for the other record type.
There is no hard and fast rule that says one approach is better than the other, but I am more likely to use separate tables if there is a lot of difference in the data stored for the two types and to use a single table if just a few extra fields are needed for one type and not the other.
Either way, the unified table solves your value list issue and can also simplify some reporting and other database design tasks.