Updated November 30, 2018
I don't sell Suzuki manuals, nor do I supply them for download. My view is that just about everyone today has a computer, laptop, tablet or smart phone, together with fast internet service, and so all I do is try to provide easy access to a range of manuals on-line that have either been given to me or that I have purchased and then scanned. For years now, I have kept a laptop in my work area so I can easily look up anything I need, when I need it and I find it incredibly useful. Given that the cost of a used laptop is about the same as an OEM piston, it is a cheap option. If I do want a hard copy manual then I typically buy them from e-Classic Bike in New Zealand - excellent quality, wide selection and reasonable prices. They also sell on eBay, and of course eBay or Amazon are both good sources for manuals in general.
My preferred third party 'how to' manuals are published by Haynes - sadly most of these are only available as used copies now on eBay or Amazon. Due to copyright ownership they are not available here. In those cases where Haynes manuals are not available new (for example for the GT750), I strongly encourage owners to write Haynes and tell them to get their act together ! You can email them at firstname.lastname@example.org. The Clymer manuals, in my personal opinion, are merely 'OK' if nothing else is available, or if you want something additional to the manufacturer's manual.