Vietnam forum

I'm looking to spend a year in SEA starting this fall (2012). I am currently thinking about flying into Hong Kong from the West Coast of the United States (where I'm from). From there I'd make my way to Ha Noi, Da Nang, and into Ho Chi Minh City. Then spend time in Cambodia, Thailand, come down through Malaysia, and fly home out of Singapore. I'm thinking I'd buy a motorbike in Vietnam. I plan on backpacking my way through the region.

What are the most common itineraries for such expeditions? Excluding plane tickets, what can I expect to pay for a year in the area? I plan on setting an outlined itinerary as my first step in preparations. What are your thoughts as to where I should go, where I should spend more time, and what I should be aware of while in the area.

Due to the fact that I plan to spend a year in the area, what is the most economical housing situation? Out of all the countries, where can I get a prolonged visa and live cheaply? Additionally, I want to get involved in some sort of a community.

Anything and everything helps. Thanks.