You need the levers. There may be a hack workaround.
SW-R610 Sprinter switches need the levers. The SW-R600 is a fully fledged shifter in its own right and doesn't need levers. I believe the SW-R9150 levers can also be used as standalone levers, but I've never tried using them myself.
You need the levers. There may be a hack workaround.