I went with flip flops only, skipped the water shoes, didn't have a problem. Drives me nuts when I see tourists with water shoes walking on the coral. That is not ok to do, it kills the coral! No water shoes will remove the temptation.
Bring a floatation device out with you in the water if you can't swim the whole time. Yes, there are maybe some spots when walking into the water that water shoes will help, but I didn't have a problem with that at Aulani or Turtle beach. Flip flops were fine walking around the pool and to the beach.
If you insist on the water shoes, please remember to be careful what you walk on.