Hi OCC.
are you looking for a flight planning system or an OPS control system?
It always depends on the scope of your operation (how many aircraft, what group of aircraft - i.e. jet or prop, etc...
If for the flight planning system, you might also want to take a look at JetPlanner or jetplan.com from Jeppesen.
As for the OPS control Systems, I would recommend SkyOps from Cyberjet.
If you require details drop me a message.
Cheers
fcit