Having spent far longer than I care to admit playing today, I took killing 87 wither skeletons to the 3 heads needed for a Wither boss. One with boss down means beacon well the beacon-y part of a beacon, now just go get the 164 blocks required. Which to that end I then finished the iron farm and it is producing iron too, by a building it slighly out of town it is far enough away from the villager breeder for them both to work So if I add my iron, gold and emeralds to what the farm has produced we're at about 50 blocks already so almost 1/3 of the way to the beacon already
Though a little heads up, if you go in to the iron farm watch out for zombies. It currently only has one wall and zombies love villagers so you may find zombies under the farm trying to get to the villagers.
Edit: I forgot to add, to help towards the beacon I'm going to AFK at the iron farm so hopefully it should produce a reasonable amount or iron to put towards the beacon I've been going through the villagers as best as I can and still not found a mending villager The perfect one would be a cheap mending villager but at this point I'd take an expensive one. We do have a new librarian though so I'll unlock the trades and some point and keep hoping.
Edit2: Damn There is an AFK timing that kicks you off eventually. Oh well guess there won't be much AFK'ing then.