The CSP is good to avoid the foreign transactions fees. Always take a back up with you just incase. Also make sure you have a Visa Signature card if you want to rent a car, you can use it as an insurance back up so you don't pay for insurance outright (AMEX does this too but since Visa is accepted more often take the Siggy). In Thailand the major restaurants or stores will take mostly Visa, however make sure to have cash on you since a lot of the smaller vendors and kiosks you will probably be purchasing from as a traveling tourist will take cash only. I had no problem pulling cash from ATMs (of course use the ones with no fees). At the airport there was a very small transaction fee at one of the currency exchange kiosks which I used when traveling back.