Reading the link on the ukmkiv's site and other info on here everyone says you need a catch can with 19mm outlets...
Surely you can use one with smaller outlets, say 15mm, and get a silicone adapter from 15mm to 19mm and run the majority of the pipework in 19mm. The reason im asking is there are catch cans on ebay for £30 delivered, paying over £100 seems a bit steep to me for what it is...