Canada Post is the normal Go To for most eBay sellers.
They have lower prices on most services, ship everywhere in Canada (and are used a sub-contractor for couriers who don't), and have world wide connections through the Universal Postal Union.
And they cover parcels up to 30 Kg.
BTW- when dealing with Canada Post only use metric measures. CPO went metric in 1974 and any other measurement is guesswork and approximations.
https://www.canadapost.ca/cpotools/apps/far/business/findARate?execution=e1s3
