First off you can't purchase the classic boards as a kit any longer, so your options here are to ring around as many dealers as you can and see if they still have any on their shelf. This is what I did and got lucky on the second call. You can also purchase them second hand from other members or ebay etc.
Your other option is to purchase the standard floorboards which are still available in kit form from your dealer. The standard boards are about 1 inch higher and angled back a little further than the classic version. Also both the classic and standard version come with new heal/toe gear lever and new longer brake pedal. The gear lever and brake pedal also differ from the classic and standard version so are not really interchangeable.
Which ever board set you aim to fit will require the following items to finish the installation on the Roadster.
1. Standard version gear actuator lever ( I bought the chrome accessory one from Triumph)
2. Standard version gear lever adjusting rod. ( I made my own from SS)
3.Brake master cylinder from the standard or classic version Rocket. I used one from a Triumph Speed Triple 08-09 model as they are exactly the same and there are plenty of cheap ones on eBay. The standard Roadster master cylinder is the same as the Rocket touring version and mounts differently to the standard Rocket version.
4. New brake line made to suit. You could also have a braided line made to make things simple.
5. A small bracket to mount the stop light switch as per photos already posted.
6. Depending on which kit you get you may also require the brake pedal and gear lever pivot bolt.
I have done this change twice as I first installed the standard rocket foot pegs and rails and 6 months later installed the classic floor boards.
Standard floorboard kit part number A9758085
Classic floorboard kit part number A9758081
Cheers