It comes with Sol. Just select it from the dropdown I think sol_extra looks a bit better.
The Corvette will be about the best setup, with a good setup that thing is fast and planted.
I only do a basic tweak of the setup as I'd prefer to keep driving than fiddling. I tend to leave to suspension stuff alone but there's some simple quick stuff to tweak after a hand full of laps to get a solid base.
Tyres: Select the softest as we're only doing a few laps.
Tyre pressures: If you find the tyres going cold despite lapping fast, lower them. If you find them overheating, add more pressure.
Doesn't it make sense to do the opposite with the tyres? In real life if they are overheating you want to drop pressure and vice versa?
Nah, softer tyre will flex more and generate more heat.
Liking this track choice though. And liking the 919 so far.