Speedplay Zero pedals have a lot of float, not "slop", and they can be dialed in with the simple (simple as in very easy) set screws on the cleat to give you as much float as you want, or even zero float.

The only really tricky thing about speedplays is the cleat install. If you don't want to fuss around and swap shims, it's best to find a reputable shop to install them for you (it helps if you buy the pedals there). Improper installation makes them the worst pedals ever.