The owner information is in the ACL AFAIK because it is a permission assigned to the ACE that owns it. So if you don't copy the ACL then you don't get the owner information either. You'll need to make a decision.
Option 1 - Copy the files without the ACLs. Then enumerate the files to set the owner on each one. If you put the files into a root folder then you should be able to set the owner on the root folder and have it inherited by all the children which would be quite a bit faster.
Option 2 - copy the ACLs to get the owner information and then enumerate all the files to remove any explicit permissions. If you are putting all the files into a root folder then you can also, in theory, set the permissions on the root and tell it to reset the permissions on all children.