This is arguable I guess, but the best layout for armor that I've got so far is everything made of steel. Mail shirt, breastplate, cap, helm, greaves, gauntlets, high boots, shield. Layering is a big problem in this version (it was to a lesser extent in 40d as well), but the above layout will cover all the dwarf's vital areas.
Since it's so difficult to get dwarves to wear what you tell them to in the current (buggy) version, I don't like to mess around beyond that. There are ongoing studies about the effectiveness of various clothing types in stopping damage as well, but if your uniform gets too complicated, every extra piece of clothing in your uniform is another chance for the AI to screw it up somehow. Generally I just let dwarves wear whatever regular clothes they have under their armor.
The best way I've found to get dwarves wearing exactly what you want is to carefully watch each dwarf as you draft them into the military. Once the first dwarf has put on everything you want him to have, station him in a room with a door and lock him in there. Repeat for each subsequent dwarf as they go into the military. This cuts down on dwarves wearing more than one mail shirt apiece, or picking up two or three shields each, etc.
If a dwarf still manages to equip something you don't want them to wear, but you need the item in question for another dwarf, you can go into their inventory and mark that item for dumping. A civilian dwarf will chase them around until they catch up, when the civilian will grab the item for dumping and run off with it back to the stockpile before taking it to the garbage dump. Then do the locking trick on the military dwarf, and reclaim the item from the garbage dump.
I can't say as I understand you not being able to find much ore, unless you're digging through an aquifer, but here's a tip. When you are looking for an embark location, you want at least one rock layer that shows up as a bright white color (not dark gray, or an in-between light gray, you want a WHITE one). You're practically guaranteed to find flux, iron ore, and coal or lignite in that layer, which means you can start cranking out steel armor in your first year.