These are perhaps what you want http://www.coolairvw.co.uk/Item/Shop_by_Vehicle~Baywindow_Products~Baywindow_Engine_Products~Baywindow_1600cc_Engine_Products~Valve_Train~Pushrods_and_Tubes~Performance_Pushrod_Tubes/AC10920175S/T1-P-T2-P-T3-P-T181_Scat_Spring_Loaded_Pushrod_Tube.html" onclick="window.open(this.href);return false;
Easy to fit, just take the rocker cover off, realease the rocker shaft, take out the pushrod, break out the leaky tube and fit the sprung one and you should have a leak free engine again.
I believe these and the Jaycee tubes with the two oil seals to be the best, the empi type that I have used in the pass have leaked.