12th Gen is definitively neat, but overkill for what you are doing. 8th or 9th gen is fine. 16gigs is fine, 8gig would also work
I really like the Lenovo m720q line of mini pcs (used/refurb) but they will not fit an hdd.
/edit: I mean an 3,5” HDD. They will fit one 2,5” HDD fine.