Welcome to the Forum!
A lot depends upon the chamber in YOUR gun. I would try a sample of maybe 10 rounds of random brass in the FL die & see how they function. if they work fine,, just use the FL set. If you experience issues,, THEN maybe look into getting a SB sizing die.
Chambers are cut with a reamer. A new reamer is sharper & usually cuts a slightly larger chamber than one that's already been used some & has worn down a few fractions,, making for a tighter chamber. Remember,, we are only talking a very small fraction amount,, but it can be important.