You can't go to Thailand without do some serious shopping. There is a lot of "turisty" stuff that I personally don't like but there is also a lof good items that you could get for a good prize, if you haggle a bit first.
Here is some bikinis - often very small in sizes, but ok in quality, at least for the prize.
Ande here is something else that you can find everywhere, sunglasses of all shapes and forms.