Not necessary to use a radial master when upgrading, some have the opinion that a radial gives better braking feedback with less lever travel than the stock mc.
The brake line fitting at the caliper for the ZTL2 8-pot has no bend, the ZTL 6-pot caliper has a 45 deg bend. Some have reused the ZTL brake line and flipped it with no issues. My opinion is that it puts the line too close to the wheel. The fitting for the mc side is the same for both. Spiegler can make custom lines or the one from ASB will work fine also.
The connector on 04-up uses two individual spade connectors as opposed to the 03 single connector, easily modded. GL