Sentrol used to be the dominant market leader in magnetic contact switches. I have probably specified tens of thousands of Sentrol switches over the years. They were then bought by GE Security and went downhill fast, and then spun off to Interlogix. They still make a good product, but the number of product options available is only a fraction of what Sentrol originally had.
GRI is now my preferred manufacturer of magnetic contact switches. Honeywell Security also offers some good options.
It is my opinion that bonding sensors in mag locks and latch bolt monitors in electric strikes should be used in conjunction with, not in place of, door position switches. They provide different functions and you can get some interesting results when you try and substitute one for the other.
For example, many access control systems reset the door unlock time when a door is opened. This is to prevent a second person from passing through the door after the first person walks through. If you use a bonding sensor on a mag lock as your door switch input, the door has the potential to immediately relock itself after a card has been presented.