Okay, here's a bit of a breakdown.
For a scribe who isn't going to go into combat, there's only 3 properties that matter.
Mana Regeneration: effectively capped at 30, as there is a diminishing returns aspect to it
Intelligence Bonus: Magic items can't take your Intelligence over 150
Mana Bonus: No cap that I know of.
(you might also want to be an Elf, to get the +20 mana and the ability to wear elf armors.)
Skills: You'll want to have as high Meditation and Focus as possible to maximize your natural mana recovery. If crafting spellbooks, you'll want to have over GM, preferably 120, in that skill, as there is a random chance that the spellbook will have 1-3 bonus properties (casting related). Some of your Focus and Meditation can come from equipment (such as Jewelry), but I believe the casting skills for book bonus properties have to be real skill.
You'll also want all of your pieces to be naturally meditation capable, or have Mage Armor if not (only some tailor armors are naturally medable: Leather, Leaf, Cloth, and I think some of the Eodon armors). Non-med items with 4 or less properties might be convertable to Mage Armor by an NPC.
Using conventional runic crafting, the most you can get on a single item is
Mana Regeneration 2
Intelligence Bonus 5 (maybe more on some items)
Mana Bonus 5
Jewelry can be imbued, but there's no current means of runic crafting.
Crafted Spellbooks can have LRC, LMC, FC, FCR, Slayer properties, the casting skills that use the book (eval and/or magery for a Magery spellbook, etc.) Meditation, Resisting Spells, Focus, Mana Regen, Int Bonus or Mana Bonus. However, the various abilities max out at 70-80% of what they might be on a wearable if they are more than "toggles" (either there or not there). There are event and reward books with better.
The Imbuing skill's "Reforging" ability allows you take a plain piece of armor or weapon (crafted with a normal tool, or bought), and a runic, go to a soulforge with an Imbuer, and reforge (choosing from several categories which are limited by the runic power level, and intensity varies based on charges used). Reforging consumes a LOT of charges off the runic for one item reforged - and you're not guaranteed to get the exact properties you want.
However, looted items and reforged items can have one or more of the following
Mana Regen up to MR 6
INT Bonus up to 10
Mana Bonus up to 10.
There are also artifacts, event items, and even a few special craftables (Pendant of the Magi, for example) that have some of these. There's also the following items slots that aren't runic craftable or reforgeable, and only come from drops, events, point collections, etc.
shoulder (cloak, quiver, etc.)
Robe/shroud/dress etc.
Shirt
Footwear
Sash
Apron/skirt
Talisman
Earrings
So, loot, boss/event drops and reforged items are typically the way to go for the core items of a scribe suit.
Typically, you can get to 25-30 MR from 3-5 armor pieces, and some of the non-armor bits.
Many of these items, by their nature, will also have mana or Int bonuses.
Once you get the maximum possible Int bonus and the Mana Regen you like, then the only properties that you really HAVE to work on is mana bonus on what's left (as long as you keep the suit where you can meditate). If your suit's not meditation capable, you're throwing away half to 3/4 of your mana recovery ability, and you can only make 3-4 level 8 or 4-5 level 7 scrolls at a time, even with 160-180 mana, before having to recover it all.