well, in bkk, suk11 on sukhomvit soi 11 is great place to meet farang travellers as yourself.
SUK11 HOSTEL will give you info about them, tho hurry if wanting to make reservation, they fill up quite often.
i would personally, if single, head over to NEP, (nana entertainment plaza) an adult venue of bars, and see if meeting any like minded local female, that would make a great 'tour guide' while you are here, and save you quite a bit of time/trouble/money, possibly, as knowing where to go and eat, if been to samui before, offer some more assistance. feel free to pm me if thinking about it, possible give you my limited knowledge from limited experience, but helpful if going that route. though if staying at suk11, only guest that check in with you are allowed in rooms after certain time.
enjoy holiday.