Old thread, but bumping it back up as I know there is another PC currently considering joining the Spellguard in the future. I would also have no issue with making use of the existing non-canon PrC Arcane Scholar as an option as well, a solution which would require no coding and just a bit of releveling.
For reference:
http://www.alandfaraway.org/node/1669
Requirements:
Skills: Spellcraft 8 ranks
Feats: Empower Spell, Skill Focus (Concentration), Skill Focus (Spellcraft)
Spellcasting: Able to cast 3rd-level arcane spells.
Class Features:
Hit die: d4
Proficiencies: None
Skill points: 2 + Int modifier
Class skills: Appraise, Concentration, Craft Alchemy, Craft Armor, Diplomacy, Lore, Search, Spellcraft
Base attack bonus progression: Low
Saving throws high: Will
low: Fortitude, Reflex
Spells Per Day/Spells Known: When a new Arcane Scholar level is gained, the character gains new spells per day (and spells known, if applicable) as though he had gained a level in whatever arcane spellcasting class gave him access to 3rd-level arcane spells. If the character has more than one applicable arcane spellcasting class, he must pick one to improve.
Maximize Spell: At 1st level, the Arcane Scholar gets the Maximize Spell feat.
Spell Knowledge: At 2nd Level, the Arcane Scholar and any party members gain a +1 bonus to their saves versus spells. This bonus increases to +2 at 8th level.
Improved Empower Spell: At 3rd level, the Arcane Scholar becomes especially adept at empowering spells. Empowered spells now only use a spell slot one level higher than the spell's actual level.
Quicken Spell: At 5th level, the Arcane Scholar gets the Quicken Spell feat.
Improved Maximize Spell: At 7th level, the Arcane Scholar becomes especially adept at maximizing spells. Maximized spells now only use up a spell slot two levels higher than the spell's actual level.
Improved Quicken Spell: At 10th level, the Arcane Scholar becomes especially adept at quickening spells. Quickened spells now only use up a spell slot three levels higher than the spell's actual level.