It should be a conceptually simple modification if you have just a cooktop and not a range with an oven and a cooktop. You would have to replace or otherwise modify the countertop since the existing hole will be bigger than the new one (which, of course, is rather the point). The gas line is probably soft copper, and could be rerouted to the input on the new unit fairly easily provided it's long enough; otherwise, some sort of a junction and extension would be needed.
Two burner RV (or residential) cooktops are not really difficult to find.