Well you already have the Clep Diaz which is a great LFO so you could keep that or replace it with the Batumi. You really only need one LFO module in a small setup. Batumi or 0chd would give you multiple ones to modulate more than one sound source which is super useful. I think you need a MIDI to CV interface for sending to your DAW and I don't have experience with the Keystep so not sure on this point.