Kathi,
It's not a cockpit rail but Burnewiin makes a Offset Insert Adapter for use with a Magma Grill. With this insert, it is easy to remove the grill when not in use. We are considering buying a Magma Marine Kettle along with the insert to go with our Burnewiin.
Where would you put your rail if you go with that method? The cockpit is not all that long. Take into consideration the rail length and height to enter and exit the cockpit, load supplies, etc. if you go with that method.