Traveling to South East Asia. Few questions.(visa, vaccines)

Hi, i was originaly planning on leaving for Thailand at the end of october tell the end of December. For a few reason i am planning on skipping town a little earlier i plan on leaving mid September if not earlier.
I will be traveling Thailand, Cambodia, Vietnam and anywheres else that comes up as an option. I don't really plan allot when it comes to traveling i just enjoying winging it. Its aug 19th right now and i yet to have any of my vaccines. How long do i have to wait after i get my shots?
Also i plan on taking 10 000 Canadian with me. From what i have heard this is more then enough for 4 months and i don't plan on living large at all. if anything i would like to bring back as much of my money as i can and live cheap on my travels. From time to time i may take a job so how do i get a visa? I heard some people say you wont even need one in Thailand. As for Cambodia apparently i can apply for one online?
I know ill be there for the rainy season but i really dont care, has anyone else done this.
A few of these questions i have found answers for but i am always looking for more opinions.