Sounds good. I will do as you have said.I used mine as well, but when i sought the help from "Skills for Change" they said I should have a letter clearly stating that the medium of Instruction used in my university is English. She then moved on explaining, that the immigration officer will look for this together with your TOR and Diploma. Which I did and my sisters application, and everything went through smoothly.
I suggest you contact your University and ask for the same letter, to minimize the possibility of requesting for additional documents. I am not sure, or read of anyone from here who did NOT provide a similar letter for the Language proficiency part. Or you could always take the other recommended options.
Best of luck!!
Yumi
Thanks