If you are so sure that you want to be in biomedical engineering, by all means take the engineering degree. Mechanical,materials or whatever its not important. You will need a PhD to get anywhere anyway as the field is very focused on research. So as long as you like research and are good at it, there are plenty of opportunities as local postgraduate programs are very unpopular with locals. As long as you have 2nd upper it wont be a problem. Of course if you want the prestigious overseas unis PhD programs you'll have to do better. Money wise in the sector it is not too bad, and if you have a breakthrough product you will really do well.