Welcome to WC!
If you look up Thailand in the search bar you will find lots of useful info from past brides in Thailand, I have found their info invaluable. There aren't many brides on here currently that have Thai plans.
Natasha from Creative Events Asia is fantastic for all the legal stuff in Bangkok. The Romance Planners in Phuket are amazing too and I will be using Gina Smith Photography, although Gina is leaving Phuket. She will spend 6 weeks in low and 6 weeks in high seasons there, so hopefully when I get my new date we can arrange it to coincide with her trips and if not she has a great team of photographers and videographers. Lisa Allen is highly recommended for Hair and MakeUp too.
We have postponed our wedding for now, but I have extensively researched our wedding on Koh lanta and have EVERYTHING planned already!!
After searching Thailand on WC and having a read, I would recommend looking up Creative Events Asia. Her website will give you a rundown of legalities. She is an Aussie living in Bangkok so there are no communication issues, she is super helpful and always replied to emails quickly.
Any more questions? Just sing out