new master cylinder or rebuild?

K so I have several choices avail;

MK 551 pro grade rebuild kit.
http://www.rockauto.com/catalog/moreinfo.php?pk=310331

Cheapest option and the mc is designed to work with manual disc.Has correct 1" bore but made from heavy cast iron.

88 Dak manual disc mc 15/16" bore

m body alum mc 1 1/32" bore

Those need the adaptor,which is fine I guess.