Please tell me your not using copper!
You have to have a licence to build and maintain a still in the US in any form. That falls under the ATF.
It is legal to brew Beer and or Wine at home in a quantity of 200 gallons a year or less.
That being said, I built one back when I was in high school 
I just used corn syrup, yeast and warm water.
You definatly need a thermometer, and a emergency pressure relief valve.
Ya that's why I love living in Canada...
..
As for the horse feed as mash
your going to
big time...
