FY is the LCC of MH and seems fine (uses MH cast-off 737s and ATRs). Flew PEN-JHB early this year while my wife also flew SZB-XSP with FY 5 years ago). Check-in and security rather efficient so maybe 1.5 to be really comfortable (and some of that is leeway for getting to PEN from Georgetown). Batik is the renamed Malindo which for me in the past usually ran a little but not too late (to/from DMK and HKG).

As for SZB (FWIW the former KUL), there is a train station with rail service to KL Sentral across the road (accessed by elevated walkway) though the walk seems rather... unintegrated 5 years ago. Not sure what the current status is. Rail may work better if the schedule fits and its not rush hour and/or raining.