Thanks y’all. I’ve already bought the 20” barreled weapon, it’s inbound now. I’ve a NF NX8 2.5-20 for it and for the 16”, I think I’ll use a Trijicon Accupoint 3-9 I’ve got lying around. The instructor said the 20” will work fine, didn’t ask about the 16” but am GTG judging by the comments.