Elephant tracks

Somewhere on here I printed off a recipe for elephant tracks which I am going to make.
The recipe calls for sour cream and also butter. I am wondering if I can use margarine, and low fat sour cream? Or will that change the recipe too much? I have never made them before so I don't know what to expect them to be, I just thought they sounded good. But DH has cholesterol troubles, so butter isn't good for that ....