N-Mosfet Rds Value Question and Use for Bidirectional Logic Coversion Purpose
Rds is the resistance between the drain and source of the transistor. This resistance causes power losses with high currents, but in your case it sounds like you are not using the transistor to drive high currents so Rds has little effect to your system, thus you could use any one of your MOSFETs. Usually smaller the Rds, the better.