Great idea to take it on track - I actually think it's safer than being on the roads! No street furniture or potholes, everyone is going in the same direction, no junctions!
There are plenty of places to get track fairings from. When I was racing my SS mine all came from a company called Ricambi Weiss in Germany, as they were cheap, good quality and also did race versions without the light holes. However, with Brexit meaning you'll now pay import tax, they may not be as good value.
The DesmoDue race series should be able to help with the best place for new SS fairings, although a lot of the bikes are adapting other fairings to fit, rather than original shape.
If I was about to go and get some fairings the first place I would look is ebay at some second-hand stuff. It doesn't need to be in good shape either, as some glass-fibre repairs and a quick spray of paint will give you a good enough finish for a trackday!
You might also want to think about a spare tank as well, just in case. SS tanks have rocketed in price recently for decent stuff, so again a beater and a can of paint might be your more cost-effective option just for trackdays.
Let us know how you get on, and post up some pictures!