Boxing exercises hand attack ability and strength, as well as good footwork practice. The hitting technique of Sanda is very practical, especially the throwing method. If you think the skills are not comprehensive enough, I recommend you to learn some sleep skills (that is, Jiu Jitsu, not judo, but Gracie Jiu Jitsu), so the skills should be more comprehensive, hehe.
You have both height and weight. If you practice hard, your strength should rise easily.
In fact, any martial arts is good, there is no difference between strong and weak, there is no strongest martial arts, only the strongest fighters. When martial arts reach a certain level, any martial arts is strong.
I hope I can help you, hehe.
PS: Muay Thai is best not to practice, it will do too much harm to the body.
Supplementary answer
Sanda has comprehensive techniques, including boxing, kicking and practical wrestling. As long as you practice more, you should be able to deal with ordinary people in real street fighting.
Boxing footwork is very scientific, and upper limb exercise can greatly improve your boxing speed and strength.
As for training, no matter what you train, the intensity of training is up to you. As long as you work hard, you can get good results. I suggest you practice Sanda and refer to some boxing techniques. In fact, martial arts are * * * and * *.
I hope I can help you, hehe.