Unfortunately you are going to need to be careful with the throttle with any road tyre if you have 400kw.
The club member price on federal 595rs is very good, and they are a good tyre. In fact, about as good as yuo can get without going to a full semi slick tyre.
Having said that, you could also consider cheap semi slicks if grip is currently a problem like federal fs201 or toyo 888. About 1500 a set and should last around 15,000klm depending how you treat them (ie how much track work among the road driving)
And yes, get rid of the stretch. That is an old, dangerous fad that does nothing for grip or handling. 365 is much more like it on a 9.5" rim.