Ive had some success at Hobo Camper Country up on Edmonton Trail. You can browse their catalog online which is nice.
https://www.hobocampercountry.ca/
I’d also recommend spending some time on the Popup Portal forum (
http://popupportal.com/). There’s a really active community full or people who maintain and renovate campers of all ages and sizes. If you find an issue chances are someone there has already dealt with it and posted an answer! I bought my camper last year and this popup forum gave me a lot of confidence in tackling a lot of the work myself.