Help me put the finishing touches on my Spellthief build

[ataraxic]

So I'm going to be this Spellthief guy soon. Coming in at level 7. Here's what I have so far:

Race: Whisper Gnome
Classes: Spellthief 13 / Abjurant Champion 5 (maybe 4)
Feats: Combat Casting, Exotic Proficiency (Eleven Thinblade), Weapon Finesse, Master Spellthief, Arcane Strike

I'm taking Spellthief 13 for Discover Spells. Abjurant Champion to at least 4, because 5th level will not benefit me with the Master Spellthief feat which maxes my caster level, though abjuration shield bonuses will go from +4 to +5.

My ultimate plan for this build is to utilize Abjurant Champion's Arcane Boost and the feat Arcane Strike for both survivability and melee damage. I've never played a Spellthief, but I can imagine I'll be stealing lots of spells that are rather useless, so I can use these abilities to sacrifice them and turn them into damage.

So, what I need you guys for is I need to decide which spells to learn and which magic items to acquire. Available spells are from the Wizard/Sorcerer list, levels 1-4, of the following schools: abjuration, divination, enchantment, illusion, transmutation. As for magic items, the only thing I can really think of would be rings of spell-storing, to save good spells for sticky situations.

I also need a final class and feat progression. I could use my level 15 and 18 feats for Improved Init and Weapon Focus to qualify for Occult Slayer, which would be a decent dip. Also I might taking extra sliences and silent strike (Whisper Gnome feats) so I can prevent spellcasting while still stealing spells and converting them to damage.

What do you guys think?

Available sources: no dragon mag, no tomes, 3.5 books only

[Lycanthromancer]

Buy a Tooth of Leraje from Tome of Magic.

Look at it. Closely. Note what kind of ability it gives you.

Your party is going to love the hell out of you.

[sirpercival]

Can you grab the Trickster Spellthief ACF from Dragon Mag?  You get much better spellcasting at the cost of all but +1d6 sneak attack.

[ataraxic]

Seeing the tooth, I don't quite follow as to why the party would love me. Besides, it is unlikely my DM will allow any of the tomes.

Also, Dragon Mag isn't allowed by my DM either. I'll edit my post to reflect which sources are legal.

[Lycanthromancer]

Seeing the tooth, I don't quite follow as to why the party would love me. Besides, it is unlikely my DM will allow any of the tomes.

Also, Dragon Mag isn't allowed by my DM either. I'll edit my post to reflect which sources are legal.

The tooths grant you spell-like abilities.

Spellthieves can steal Sp abilities without taking them permanently from the steal-ee, meaning you can cast Greater Magic Weapon (CL 20) on your whole party an unlimited number of times per day.

And it's not Frank & K's tomes. It's TOME OF MAGIC, a book from WotC.

[ataraxic]

That is a clever use of Steal Spell-like abilities.

And when I say no tomes, I meant no Tome of Battle or Tome of Magic.