What other rails do you have available?
You could use Mosfets, might be easier to deal with, there are logic level mosfets if you don't have other intermediate rails. Or you could use optocouplers for reliability and switch on the 48V rail but you probably want fast switching to avoid heating the mosfet, so driving the gate hard to the appropiate voltage and back to ground is optimal. Mosfets are usually prefered over relays as they waste less energy and dont have arcs at the contacts.
In any case, clamping the load with a diode as if it is inductive is a good idea to avoid any kick back. You don't really need 10A diodes but don't go with too small ones either.
JS