Go to samui webcam on the you tube and check out Bondi bar and Outback bar cams both in Lamai
when you find these places when actually in Lamai you will find the girls close by and on Bondi webcam you can see them around the boxing ring.
then there is the drag leading up to the Reggae bar in Chaweng beach which is a 20 min drive up the road from Lamai . there is a place in soi green mango but the girls a very expensive.
there are few bars in Mae Nam as well which is a drive from Lamai to the top of samui and down over the other side , the bars are spread out. you will see them and hear them at night, its worth a crews by on a moped, I like the more chilled out vibe there and met some strangers got drunk played pool and met a couple of good girls and had a great time.
must be plenty of places but they are the ones I know of. Always a great idea to get on tinder or what ever is popular these days and arrange some dates before you get there.
hope you have a great time, I am positively jealous of you.
have a LEO and ICE for me