^^^ I managed to order a Dewey Rod straight from the manufacturer in the US, just before the Canadian dollar tanked completely. They have great service, massive product selection and fast shipping. They even have cleaning 'kits' you can order that come with everything you need (rod, guide, jags, brushes, patches,...) tailored to your specific gun & calibre.
Their rods have the standard thread size, but the rod end is 'male' (comes with a 'female' adapter for other manufacturers jags/brushes).
They recommend going with a rod 10" longer than your barrel to accommodate the rod guide & any other potential clearance/length issues.