Hello!
My name Vasiles, but you can call me Bill.
I'm a fluent English speaker (not native), who has past both the C2 level and the IELTS exams. I've taken part in the creation of such exams numerous times in the past.
The content you're requesting can be put together in 20hrs of work; though I would have to request further information before going about it.
Should it be in British English or American English? Is there any specific educational methodology you would like the test to follow? What is the average age of the participants?
Looking forward to your reply!
Thank you in advance,
Bill