I've got nearly all the ingredients required to get this sucker going, so all that's left is finding someone who can transmute metal. Or somesuch. I'm not clear on how that works here, so recommendations are welcome.
In any case, I've drawn up a rough plan of where my foci will need to be located, and how big the circle has to be. Nothing's to scale, but it is color-coded. Purple is chain, teal is sensory foci, blue is the caster's foci, and red is the human components. If there are problems with my plans, please let me know now, because it's such a pain in the ass to refigure all this stuff on short notice.