I brewed my own variation of this yesterday and I'll let you know how it turned out. Here's what I did:
brewed with RO water: For my mash water I used 3 grams CaCl2 and 5 grams Gysum (CaSO4) and for batch sparge I used half of those amounts.
Grain bill: 10# 2 row, 2# white wheat, 1#...