How do I install GFCI on multi wire branch cicuit?
I believe I've seen that GFCI isn't recommended for high load appliances, particularly those with a motor (e.g. sump pump) and that it's not even required if the circuit is dedicated with a single outlet.

If you insist, then consider separate GFCI outlets for each device, wired in a double gang box. The GFCI will function perfectly normally since each is only protecting the outlet and not any downstream devices. That said, I would label this box as containing two separate circuits, so that anyone working on it in the future knows to turn both breakers off.

If you find and were to use a double pole GFCI breaker, I'd worry that this would confuse any electrician that works on this in the future, since that would usually indicate that a 220v device is installed on that circuit.