Looking into used slicks or semi-slicks from top end club racers might be an option too. They tend to throw (sell) perfectly good sets of tires away after a weekend - they've still got plenty of life left in them, just not "front running" life.

Thanks for the replies!

I think i'll probably give semi-slicks a try first. Maybe they already offer the grip i'm looking for, who knows.

The problem with asking local racing clubs for spares is that we don't have any tracks in switzerland. I'll be sure to do some research and see what i can find, but motorsport in switzerland is simply not something you "find around every corner". Guess i'll make some phone calls and start asking around at the track next time.

Thanks for the link Tristan, i'll have a look into that, since they have a dealer in switzerland.