I ship regularly from Oregon to my condo in Bangkok …. Be sure not to value the package over $20 US or the taxes in Thailand will be huge … I ship via Fed Ex (cheaper) and a 2 lb box costs about $135 to ship
Oh and yes the bank will give you a letter if you ask, the immigration office will have the form for you to take to your bank for verification, if you’re in Bangkok, the banks all have branches on the main floor of the immigration building