Personally I don't like the quality of most minilabs developing my film, much less coating it...not that I wouldn't like to see a trained emulsion chemist in every minilab, but so long as photography requires consistency I don't like the idea of my HP5+ being coated in my local lab next to the grocery store.
I'd just like to chime in and say this is an incredible project though, and I had a pang of national pride to see the familiar Pura brand milk in your fridge next to the emulsion. 5 generations of dairy farmer will do that to you, but please keep us posted while we dream.