Wiring between gen transfer panel and 125 amp sub panel
I am surface mounting a 125/30 amp transfer panel above a flush mounted 125 amp sub panel in an interior closet. Should I change out the 125 amp breaker that feeds the sub panel in the main panel and use nm wire between the transfer and sub panel or is there another better/easier option. The sub panel has 30 single-pole circuits for the house. All 2 pole breakers are in main panel. Thanks in advance.