It has/have to be (to have)
The syntax is wrong (and punctuation would help as there is an infinitive phrase):
What kind of person has it to be, to have no doubts about your choice?
"Has it to be" can be restated as "must it be"
Or the whole thing can be restated as
What kind of person must it be, to have no doubts about your choice?
which gives
What kind of person must it be, who would have no doubts about your choice?
and an improvement would be:
What kind of person must they be, if they have no doubts about your choice?