HI, guys! Urgent need help~

I am going to pay a substantial amount ( around RM20K )in British Pound. I m going to pay via international transaction locally but in pounds.

May i know if Aeon Watami offers the best rate? Do i eligible for the 3% cashback? It is unlimited cashback?

After several research, i came to conclusion that though MBB 2 cards premier both infinite and AMEX offers 5* treat point for foreign transaction, however, the conversation rate and the bank rate us kindly of high as i am going to pay in a very huge amount.

Any suggestion? Thank you!!!~

PS : My parents personal income should be higher than min. requirement for any Infinite/Signature cc from any bank. So please provide me with some suggestion on which cc should i use.