A custom-built laptop for under $1,000 is generally hard to find (our own custom-built laptops start at $1,000). There are a handful of companies that ship to Canada, but the shipping costs will run in the hundreds.
To elaborate on my rather vague response... Custom build laptops are expensive. Entry level, non custom built gaming laptops start at around $1000. to help answer your question better can you tell us what is the computer going to be for? why does it need to be a laptop? why custom?