I'm starting to think 3000+ psi and 21lpm would be too much without a surface cleaner.
21lpm is the minimum you want.
I had 21lpm and a twin turbo, felt it was too slow.
So got the 23lpm machine, that extra couple of litres makes a difference.
Don’t go for anthing under 21lpm, you’ll regret it.
Forget the FSC. Just get a 21lpm machine and a twin turbo nozzle and you’ll be more than happy.