Persons who are caring for a hard-to-place child on a foster parent basis and who have applied to adopt the hard-to-place child and to receive payments for the care and support of the hard-to-place child shall be evaluated as to their suitability as adoptive parents by means of an adoptive home study. Persons who are caring for a hard-to-place child in the state's custody and who wish to be appointed legal guardians of the child under AS 13.26.132, and to receive payments for the care and support of the child, shall be evaluated as to their suitability as guardians by means of a guardianship study. A home study or guardianship study shall be made by the commissioner's adoption staff or on the commissioner's behalf by an authorized agency or individual that provides adoption services.