I gave up on the dating sites, as tbh, so many are after money in the end.
Think it's been said before, but the best way is just to choose a nice resort, fly out there as a holiday and chat to some girls while you're there - I bet you can't easily go wrong.
I used to say I preferred Filipinos to Thai girls, as the Thais are more switched on when it comes to seeking money - but I'm of the belief Filipinos are just as bad now.
Of course, not everyone is like that, but sadly, many are.
Also, I can tell from some of the profile pics these girls were not all poor ... latest mobile etc. The really poor girls in the provinces, I can understand them asking for help just to buy food, but as I used to say, "You managed before we started chatting, so you can get by without extra money", and at least let a relationship develop.