Hi all, late to the party as usual, but anyway...
Most of the sensors, bar the KWS, seem to be passive based. What you might need is another two additions to spice things up I think.
Heat - Visible to passive sensors - Countered by Silent Running, Heat Sinks - Reduces Detection Range when in SR, Increase when not or when stations deployed
ElectroMagnetic (Radar) - Visible to Active / Passive - Countered by RAM coatings - Reduced range when Retracted, Increased range when deployed
Visible (?) - Visible to Mk1 Eyeball (maybe LIDAR) - Countered by Reflective Armour (actually visibly mirror the starfield) - Countered by Sensors above
You would then have 3 options top choose from but they are in many ways exclusive and could be tailored as people have already mentioned (signature, power draw, module selection etc).
Thermal -> Already done - No shields
Radar -> Passive = Short Range unless the other guy is radiating OR -> Active = Long Range but EM signature like a mountain - High Power Draw - Imporved weapons lock (chaff!)
Visible -> Active = Pretty general improvement but middle power draw, deploying increases detection range, armor slightly weaker
In addition, if you want you could substitute the Radar with LIDAR but then you run into 'balancing' issues with reflecting armor. As a way overpowered Visible module you could have a holographic protection system that splits the ships into one real and two false causing confusion. Could be launched similar to torpedoes. Have ammo requirements.
@micky1984 - Ever run in the Fincastle comp?