Hayes 9s reliable! you must have got a different brake set from the other 3 sets I have had. I have some Avid BB7 cable discs on my single speed and with 180mm rotors on, they are as good as any hydro brake I have ever had, including Hopes, Shimano, Avid, and Hayes. Also very reliable and have lots of mudulation and can be adjusted very easy for total drag free riding. Had a few other sets on other bikes and have always been way more reliable than my other brakes.
If you mustnhave hydros for some reason. then I have found Shimano hydros to be very good, I like the older ones before the latest Servo wave ones. The SLX ones from Merlin look like a good bet. Spares are harder to get thiougn for Shimano and expensive if you can get them. That said all the Shimano brakes I have had never required any! Last Hope brakes I had were easy to get spares for, but I needed them!