Hello,
Here the seed bank i suggest you;
http://www.cannabis-seeds-bank.co.uk/
http://www.nirvanashop.com/
I would suggest attitude first. (Not biased but just had very good experience with them) Fast and stealth shipping.
If you are nervous that it get detected at airport. Get their stealth method (T-Shirt) and you wont have any problem (you have a very low percentage to get it caught) If they find you re seeds, the company will resend you re order for free because you took their stealth shipping method.
Are you planning to grow outside or inside? What kind of climate is there in Thailand at this time of the year? This will help for suggesting you some strains.
What kind of budget you got? Do you plan to buy nutriments? If its indoor what kind of set up will you use? Hydroponic? Soil? If its you re first time and doing it indoor, i would suggest you to start in soil to get used to the plant and all the things she will need.
I will wait an answer from you to give you further advice.