JST 18:22 also describes them as "holy men, and were sent forth after the order of God"; and the footnote for 19:1 says "angels" is from the Hebrew word for "messengers". All this suggests they were men who held the Melchizedek priesthood.
Also, one possibility you missed is translated men - thus, physical, not yet resurrected beings.
(OT: Yes, this is zil, now zil2, because zil is seriously messed up. )