Converter if to a Hyd or solid flat tappet only require the cam, lifters and correct length oil through pushrods. Depending on what you pay for pushrods is the price difference breaker.
I myself have most of the parts for this on a shelf and require only pushrods that oil through or the proper length.
I suggest a roller cam over a bud if the roller doesn’t need longer pushrods and the OEM Hyd lifters can be used over again though there cheap as heck.