I saw you had been training MMA, so what about doing Brazilian JiuJitsu (they use it in mma fight, isn't ?). There are several places in Saigon to train, but I don't know where you live so it is difficult for me to recommend one.
Nevertheless, I train at the Saigon Luta Livre club in D3. I't really cool I recommend you to come and try one class at least
Anyway, good luck in your research to find a good place to train !