Private Asia tours to Vietnam, Thailand, Laos, Indonesia...
 

Could your guys offer some tips?

We were happy with Tonkin, whom we used for private tours in Vietnam, Thailand and Laos.

We used this fellow below aka "Zoom" for our port stop in Saigon and were very pleased. He was born there and taught English in school so he knows it very well and he is most courteous and reliable and his rates are very reasonable.

http://www.saigonprivatetour.com/about_us.html

What are you looking for? Someone to organize a three-week tour of SE Asia? Someone to manage a port stop on a cruise?

I've never used a tour company in SE Asia (with the exception of Burma). It is remarkably easy to manage independently.

If you hire a company, be aware that they usually include all kinds of things you may not want or need. Be clear about what you do/don't want included. Otherwise, you may end up paying for guides you don't want or airport transfers at 10x the price of getting a taxi.

Look at Authentic Asia for a tour company specializing in those countries.
We had good luck with Tonkin in Vietnam.

I usually travel independently, but I did use Tonkin the last time I was in Vietnam for a side trip to Sapa.

Your question is too vague and too broad - what exactly do you want?

Travel Southeast Asia, you should chose September to November.
Thailand: Should visit historic center like Aytthaya Sukhothai, Chiang Mai and national park.
Vietnam: Sunset floating through Halong Bay, getting measured up for a suit in charming Hoian, trekking in northern hills of Sapa.
Laos: Sunset or elephant trek from nothern of Luang Prabang, tubing in Vang Vien and Wat Phu in Champassak.
Happy travels

If you go to Indonesia you should definitely join Indoneo's adventure trip: http://www.indoneo.com/collections/all ; From Journey to the Heart of Bali, The Great Mahakam River Adventure, The Mount Rinjani Climbing, and other adventures. It's definitely worth a try while you're in Indonesia!