I need to book a flight from SIN-LHR, currently musing between booking BA or Malaysia Arilines but I'm unsure about my luggage allowance (I am BA Silver):

1. If I book an WT BA ticket I will be given 2x23kg, will I be able to add on a discounted 3rd bag (usually circa £35 for this route?)

2. If I book an economy ticket with Malaysia Airlines, will my 2 bag allowance be hourned as I'm Silver with BA?

Thanks in advance