I'm sorry you're finding the site so frustrating. Let's see if we can get you sorted out a bit.

First off, I've distilled your query down to the key points as I understand them. Let me know if I got it wrong. Please understand that the members of FlyerTalk are a helpful bunch, but we tend to be very do-it-yourself when it comes to travel. That is why the responses you're getting may be less specific than you had hoped. They mean no disrespect by posting suggestions that may strike you as too vague or with too much jargon, so please be patient, and you will find that most members are only too happy to get you pointed in the right direction!

I want to start by emphasizing that the likelihood of finding a guide who will travel with you from start to finish, and who can skillfully cover all of those very different countries, is slim. And yes, if s/he exists, it will cost you a tidy sum. In my opinion, you will be much better off relying on several local guides, each one being thoroughly knowledgable of his or her own locale.

So, given that you're completely new to international travel, and since you are interested in undertaking a complicated trip that would be challenging for even the very experienced travelers on this site to plan out, I would strongly encourage you to use a travel agent who specializes in Southeast Asia travel. A skilled agent will help you to develop a sensible itinerary, with the right amount of time in each place, and in the right order based on air travel, etc. A specialist will definitely be able to book the types of accommodations you've described, possibly including a home stay (with a local family), village camps, small guest houses, or even hostels. Such an agent will also be able to set you up with reliable local English-speaking guides in each locale, and can even arrange for this person to meet you at the airport when you arrive. Very importantly, the will handle the necessary visas for Vietnam and Cambodia, and can give you all sorts of other advice about things like changing money, what to bring, etc.

Not all travel agents (also known as TAs on this site) offer airline bookings, so make sure you select one who does, because you will have to set up several flights, and will greatly appreciate having somebody you can call to fix things for you if something goes awry with a flight schedule mid-journey.

This type of agent will charge a fee, but it will be much less than the cost of a companion for the entire trip.

Unfortunately, the only Asia travel specialists I know personally, tend to focus on a more high-end type of travel than you've described, so I can't really recommend one. However, try searching google or bing for "Asia Travel Specialists" and you'll see plenty! Also, as mentioned by another member, you might do some reading on websites like www.tripadvisor.com and www.lonelyplanet.com and www.roughguides.com for ideas of places to see, recommendations of agents and accommodations, etc.

As far as a retirement destination is concerned, I think you will probably want to focus on Thailand and Philippines. Both have been destinations for many, many western expatriates and retirees for decades, and you'll find that English is widely spoken in most of the more populated areas. I'd start your research with Chiang Mai in northern Thailand (just have a hunch you might like it).

Good luck, and let us know if you have more questions!