I received a PM asking what I knew about about the Purple Dragon gay tours to Vietnam. My two trips to HCMC were organized through Utopia and I notice from the link
Purple Dragon offices are in the same place as Utopia offices were.

I dont know the history but there was court case about soft porn, and my guess is its still the same business.

This website on the various tours is impressive and whilst the company has been around 20 years ,I dont know who operates it now. I intend to spend some time browsing all their tours as some of them look just what I am have been searching for. Having a tour guide in Vietnam was a huge bonus. Straight friends have recommended the Halong bay cruise

http://www.purpledrag.com/vietnam/index.htm

here is cut and paste from the home page of the link you sent

Purple Dragon, Ltd.
Lobby of the Tarntawan Place Hotel
119/5-10 Surawong Road
Bangkok 10500, THAILAND
Telephone: +(662) 238-3227
Fax: +(662) 634-0292, 653-6784
open Monday through Friday, 10:00-18:00 (Bangkok time)