Agreed, Thailand would be a good option. Phuket would probably be the best option as it offers everything for a long stay, choices of accommodation types from rooms and guest houses, apartments to 5* resort hotels, great beaches, bars, restaurants and a variety of day and evening activities. The main choices on Phuket would be Patong, Kata, Karon, Kamala and Surin. Patong being by far the busiest but not my favourite place. All places have strong nightlife areas and meeting people is very easy, you just need to take time to engage with the freelance girls who visit the bars and discuss your wants and their flexibility!
IMO Bangkok and Pattaya would be unbearable for 2 of 3 months but each to their own.....
Thailand has been largely closed to tourism since March last year and whilst it is now possible to visit, it is difficult. The other point to be aware of is that the nightlife and bar scene has been hugely affected and many of the bar girls and staff have returned to their homes in the north. Nightlife and the choices that came with it have temporarily disappeared.
Best of luck with you planning and final choices