I have not been to Amantaka, but for service and facilities, I might actually give the nod to Yara over Sara. March would be beautiful in the Turks and Caicos but there is not much to offer culturally...just good diving if you are experienced, and a beautiful beach. For me, the best part of Sara is the area temples. It's less about the resort.

I did trip reports for each if you want more detail.

And if you can handle the heat, July is a bargain at Yara....full board, better rates. Slight chance of a hurricane, but that is slight.