Nope, can't use an FM receiver with your AM transmitter.
Yes, your AM Mini-X receiver will work with your AM transmitter as long as your TX is 27MHz. If your TX is a Perfex KT-2 and your Mini-X receiver is the V1.0 then there is no problem as far as I know. If you have the V2.0 Mini-X receiver then you may experience problems with this combination as a few of us in this forums have.