Buy various sets of cheap rollers first to work out what weight you want, remembering that cheap ones do wear out quicker. No point wasting money, once you have your setup worked out, then buy the sliders. I am using Dr. Pulley sliders and do like them. I have heard that when using Dr. Pulley sliders, to use 1/2-1 gram heavier that you would with rollers, though I don't know if there is anything in that.