As for the black knights, there is one very easy way to get a hold of tons of those.
Take the quest Necromancer Meshmere gives you in Montero shafts. Provide him with 300 miners, 1 Dwarf Warrior, 1 Cannoneer, 1 alchemist and 1 Giant. Now he will transform dwarves into undead for you. 1 Black Knight = 1 Cannoneer. Since Cannoneeres are plentiful, so are the black knights in this case
Have him transform like 300-350 cannoneers into black knights and you should have more than enough till the end. Or maybe even more, if you have no problems with the losses.