Sea life bangkok is definitely a good place to visit! It is really big and an indoor area (full aircon area). It’s located inside a big mall called siam paragon so after you enjoy the sea life, you can go directly to have lunch with various choices and go shopping for souvenirs or clothes!
For the wax museum, it is great but not so worth it. The museum is too small and just so so.
Overall our experience was really great!