I'd pick your own inverts...not all the inverts in the reef packages go together or should go in that size of tank.
example, for the 20-55 package they give two brittles, these stars get huge...and would out grow a 20-55gl tank.
in the 55-100 Gallon Reef Package they put CBS and peppermint shrimp together, the CBS will eat the peppermint shrimp.
So, if you're ordering inverts for one tank, just pick what you want, and make sure they're compatiable with each other and your tank set up.