swriderdss welcome to the best Silverwing forum on the web. Here's a link to make your own backrest.
Leroy Beal backrest mod.
The backrest that SteVe mentioned is probably the best money can bye. I have one and it's nice.
I also have the Leroy Beal backrest mod and I've made a few for others and it works just about as good.
I would read through and look at all that are available before just getting the first one you see.
If you plan on doing your own maintenance you'll find you can do anything you need or want with the service manual and help from this forum.
I add the paragraph below for most new members because there's a lot of information in the links and may save you some work.
Here are some links(3 below in blue)that will help you learn a lot about your Silverwing. If you can't find what you need in the links below the search on this forum works good, and if you still need help just ask and someone will do what they can to answer your questions.
Maintenance, Tips and HintsMaintenance "Pictorials" Accessories-Modifications