The thrust-to-weight ratio is going to vary greatly for small thrusters (and hydrazine monoprops are generally quite small), with the very smallest having much lower thrust-to-weight ratios; mass doesn't scale down linearly with thrust at the low end.
For example, Airbus makes 1N, 20N, and 400N hydrazine thrusters, all pressure fed with similar operating characteristics:
Thrust (N) Mass (g) TWR
1 290 0.35
20 650 3.14
400 3800 10.73
Aerojet Rocketdyne also offers a family of hydrazine monoprops with generally similar TWR trends.
Astronautix doesn't list any hydrazine thrusters above 1kN. The most powerful I could find in my search were the AJR MR-80 used on the Viking Mars lander (3.1kN, 37:1 TWR), and its derivative, the Mars Lander Engine used for Curiosity's skycrane, at 3.6kN.
I can't find much info on peroxide monoprops.
Quoted masses for pump-driven bipropellant engines should include the pump mass, by the way.