Simple, you may open a bank account in one of the local banks where your transfer the funds into. Otherwise you may transfer funds directly into the bank account of your real estate agent that is engaged to purchase the property on your behalf; make sure that you only deal with reputable and professional agencies. Make sure that your transfer shows all correct bank-details (Account name, account number, branch name and address, swift code and type (current or saving) of account) as well as the full address details of the receiver PLUS a description of the reason for transfer.
This description could be: “Property Investment Thailand”. Only if your transfer exceeds the amount of 10,000 USD you should ALWAYS request an official so-called “Foreign Exchange Transaction Form”. This “Foreign Exchange Transaction Form” will always allow you to re-transfer funds out of the Kingdom of Thailand. As you might know; normally one is not allowed to bring money outside of Thailand. Only with a “Foreign Exchange Transaction Form” you are allowed to send money, for a similar amount, out of Thailand as it proves that you ever transferred funds into Thailand. (If you buy a property and sell it later, it will become helpful).
If you ever register a “freehold” (foreign owned) condo into your name you must be able to show a “Foreign Exchange Transaction Form” upon transfer at the Land Office. “Foreign Exchange Transaction Form(s)” are personal documents that you should always keep in file.