>>If I want to have someone whip up some heavy duty chain armor (think tanking quality, I don't care about weight or hinderance) from the regular and high/low steel variants (so no rare metal) could someone tell me what I would want to order? Armor is way more complicated than weapons.

For the material you want to get the heaviest mix of high-steel that you can (67% steel/33% gold/plat). That will give you the highest physical protection rating (90) along with the most weight you can get from non-rare mats. As for the templates you want mail. So a plat-weighted hi-steel reinforced mail hauberk will give you the heaviest chain armor you can get without rare mats.