Beru connectors go on solid core leads, the leads have no resistance and the beru connectors have resistance built in. This way each lead displays the same impedance regardless of length. Technically a superior setup.
Magnecore / Spiral wound / Supression leads use RF supression built into the lead and not the connector. This is a cheaper alternative but the resitance / impedance varies with the length of the lead.
Some aftermarket CDI setups like the MSD specify NOT to use solid core ignition leads (ala Beru) as it will void the warranty.
A great company in Aus to order custom ignition leads from is Queensland Ignition Leads (07) 3886 6700 MQileads@aol.com
, they are doing a custom set of 8.8mm spiral wound supression leads for my 930 EFI mod for only $80AUD ($60USD). I am doing a 3 coil pack wasted spark EDIS on a EMS Stinger ECU.