I find parcels from the UK and Europe to arrive slightly faster than domestic or US parcels. Allow 15 -20 days nonetheless. If it has not arrived by then, use eBay messages to ask for shipping date and Delivery Confirmation number. He probably won't have the latter, but that is not a problem. The DC is useful for the seller not for the buyer.
If the parcel will not fit in your mailbox, the postie will leave a Delivery Note and you will be directed to the PO where he leaves the parcel.
All international postal shipments travel under the Universal Postal Union Treaty http://en.wikipedia.org/wiki/Universal_Postal_Union
No matter what the origin of the parcel, Canada Post will treat it the same way.