Thanks for all the answers so far.... here comes a follow up question:
what about brake fluids. Just today called to a Castrol reseller and the best price for Castrol SRF fluid (1 litre) was 79 euros

(
69,18 GBP). That is quite expensive. I'm about to change the original brake hoses to steel hoses and was wondering what would be ideal fluid for street / track use.