Is the Casio fx 82 ms an accepted calculator for the SAT?

Probably not, I didn't see that name under the list of calculators accepted, unless it is a part of a series or something.

https://collegereadiness.collegeboard.org/sat/taking-the-test/calculator-policy

If it's not on the College Board's list of permitted calculators, it won't be allowed on test day.

I suggest taking a look at the TI-84 Plus CE. It has proved to be a worthwhile investment as I have used it on many occasions to help my peers and work on otherwise difficult calculations. It is also important to note that it will continue to be useful, as you will need such a tool for more complicated math courses in the future.