I have several of the Explorer 16s and I'm an avid, however I have not had the opportunity to demo Kerhuel's blockset. I would be interest in get your feedback after you had a chance to use them in your project.
Until I've had some experience with Kerhuel's blockset I'm unable to give you guidance on your first question.
However, as per your second question, you have basicaly two options. You can simulate an ECG input via data stored in a file or you can use an ADC to bring live data directly into Matlab real time.
Of course, you could record the live data into a file as well for repeated testing of algorithms.
If you have any other questions, feel free to contact me.
BigDog