"Magic" type? You mean indestructible or with various effects? They are just enchanted basic items. I believe you can find a few pieces in the world, but for the most part you'll just have to make your own using the Enchant spell or scroll.

Well, I mean the one from the walkthrough:
Plated Chest:
*+7 AC
*-5% Stealth
*-4% Casting
*-4% Protection from Magic
*Object knowledge: 15
*ST: 14
*DUR: 90
*Price: 1600

Magic Plate Chest of extra Protection:
*+10 AC
*-5% Stealth
*-4% Casting
*-4% Protection from Magic
*Object knowledge: 35
*ST: 14
*DUR: 90
*Price: 1800

I already found the "Leather Chest of extra Protection": the Blacksmith has that.

I'm fairly positive these variants can be bought or found. Enchanting only adds certain modifiers but as far as I know doesn't modify the name like that.

As for the meteor sabre, that's a quest item and normally can't be obtained outside of its related quest.

Thanks; ok, then I'll have to keep looking... thx!

Magic Plated Helmet: Twin Traders
Magic Plated Chest: 1st Tomb on the left on Lvl 7
Magic Plated Leggings: Rebel Camp; on way to Krahoz on a high ledge (telekinesis)