Unfortunately, your wife can not sponsor you because she is not a PR yet. By overstaying before, you have shown immigration not to trust you. Now you say you want to visit. They think you will overstay again.
With CEC, there is no duty to stay in Canada so she can come and stay with you for as long as she wants. You and her can do the medicals whereever you can find a DMP so doing them in India will be fine. I do not know if you will get your medical request at the same time. You will have to wait and find out.