I have a customer who cant afford versalock and does not want wood ties for her steps. So what I was thinking is to use foundation block 6" rise and 16"deep for only $1.50 per block. I plan to use two coarses for each step. (Meaning bury one then stack on top)I have done this before this way before with 8" foundation block. does it matter how steep the hill is when choosing your rise height?