Mixing brakes does not raise any functional red flags. Clearance and fit are the only real issues. Make sure that your replacement caliper has sufficient REACH when paired with the new fork to work with your wheels.

However if you are changing your fork for different reasons, you may want to look into a conversion adapter. https://www.amazon.com/Profile-Desig.../dp/B0028N14GQ This will allow you to use the wider variety of stems and bars now being offered. And will not entail other considerations already raised. And will be much less expensive.