i love my AMEX platinum card, and their membership poitns are used across a variety of airlines, so you have a lot of flexibility. Especially if in 1.5 years you start thinking, "eh, not so into thailand, i want to go somewhere else."

if after you do all your research and you think of going down the platinum route, please consider telling them that i recommended you. just PM me before you do it, and i'll give you my name. I can earn some miles as well while you get started.

but since it seems like i'm getting something out of it, do your research on all the different cards you have in mind and then look at the platinum benefits. i think you'll find the service is worth the high annual fee.