NITTO - NT555R

That 325/30R19 size is not an easy size to find.
Here's the Nitto webpage for the NT555R - NT555R D.O.T.-Compliant Competition Drag Radial Tire | Nitto Tire. As that site shows, That tire does NOT come in the size you're asking about. The NT555R is rated at 8/10 for dry road conditions, but only 5/10 for wet road conditions. It also only has a 100 treadwear rating (the factory Kenda tires are rated at 300), so it won't last very long on the road.

The Nitto 555 G2 (NT555 G2 Summer Ultra High Performance Tire | Nitto Tire) is supposed to be available in a 305/30ZR19 October 1. Its treadwear rating is 320, slightly better than the factory Kendas and it's rated 9/10 for both dry and wet road conditions.

@silver fox it is a beautiful tire and looks badass on the back of the Sling. It also performs great on dry hot roads. Sadly that is the end of the good points.

It is a dangerous tire to run on damp roads, is expensive and wears quicker than advertised. @Cameron Roberts and @Tango may be able to enlighten you more as they owned those tires.

The 555g2 that @BKL listed is an excellent Sling tire. Lots of people run it.

^ Agree with the above.

It is a R compound tire and is meant to be used as a drive to the dragstrip in fair weather, make passes, and drive home in fair weather. Not really a good choice for a SS.