To save iSAMs development, why not have just one exams module that serves for external & internal exams, especially as you can already customise basedata in the external module. That would save set up, time, money etc for schools too. You could just have a box that you check when you set up a new cycle that is either internal or external. And then you could run two cycles (one of each) in the same month too, as I am sure many schools run mocks in at least one of the Nov/Jan/Jun external periods too.