Organisers said lese majeste fugitive Jakrapob Penkair will likely take part in the celebrations too.
The bus trip will begin on April 13 from Bangkok, crossing the border checkpoint at Aranyaprathet into Siem Reap.
The tour will include the visit to Angkor Wat and Tonle Sap. The meeting with Thaksin, and possibly Jakrapob, is to take place on April 14. The return trip is on April 15.
The tour package will include meals and accommodation at a four-star hotel.