Playing a 3.5 Spellthief - Thoughts?

[Felger]

So, I'm playing a spellthief/sorcerer, and I've been trying to play it as a half-spellcaster, half rogue-type character. Currently, I'm at lv 4, 2 sorc/2 spellthief and I'm looking at what to do with the character, since it's fairly weak on both the spellthief side and the sorcerer side of things.

I've been looking at a couple of prestige classes that might mesh well with the spellthief (I've noticed in almost every spellthief thread I've been able to find, everyone recommends Unseen Seer, from the complete mage)

Specifically, I'm looking for several properties in the prestige class:

Extra Sneak Attack damage (For spell-stealing, and for doing decent damage against non-spellcasters)
Extra spellcasting abilities (actual spells known progression)
Preferrably rogue class skills (I'll be functioning as the party's rogue when it comes to traps, sneaking, etc)

Anyway, the prestige classes I've found that fit this bill are:
Arcane Trickster (DMG 1)

Pros


Most sneak attack damage of the three classes
Actually has disable device as a class skill (Also, ranged disable device with Mage Hand)
Impromptu Sneak Attack is really nice for the spellthief (stealing spells at a whim)
Better saves


Cons


Not as many caster-specific special abilities
Lower Base Attack Progression
d4 hit die

Unseen Seer (Complete Mage)

Pros


Extra spells known (Great since I'm a sorcerer as my other class)
Divination Bonus is a marginal bonus, nice for self-buffs and other stuff.
Silent Spell Bonus feat
Better BAB progression than Arcane Trickster


Cons


d4 hit die
Lower saves
Divination Bonus means drop in spell level for other spells, which won't be too bad, since I'm taking a spell level bonus with Master Spellthief, and my spellthief levels.
Has search, but no disable device.

Daggerspell Mage (Complete Adventurer)

Pros


Same BAB progression as unseen seer, higher than Arcane Trickster
Daggercasting. Major plus there, using dagger attacks as deliveries for touch spells, effectively bonus damage for dagger attacks. Lots of bonus damage.
Don't have to put away daggers to cast
Pretty nice class abilities relating to combining daggers and casting.


Cons


Delayed spells known / per day progression compared to the other two classes.
No Disable Device or Search as class skills.
Lowest Sneak Attack Progression of the three
Has to use daggers, eliminates other, slightly higher damage light weapons.


In any case, looking for input on these, or any other ideas anyone has on classes / prestige classes / feats / skill tricks, etc. If it's helpful, the character is neutral good, and acts as an somewhat freelance agent for a semi-autocratic coalition, so would have reason to be secretive. I can post more character description if it's helpful.

[Waker]

I prefer Arcane Trickster myself.
I would say stay away from Daggerspell Mage, the class would require Weapon Focus and Two-Weapon Fighting, which is just horrible when you consider you need more caster levels than rogue levels to qualify for the class, so your BAB is gonna be crap, not to mention your low HP.

You might want to consider the Spellwarp Sniper as well. It's Sudden Strike damage rather than Sneak Attack, but that doesn't matter much since the only difference between the two is that you can get Sneak Attack from flanking. And unless you want your armorless, low HP character in the melee you won't notice the difference.

[Bakkan]

A feat to consider is Craven from Champions of Ruin. It adds your character level to your damage whenever you sneak attack, which won't help your spelltheiving but will add a significant boost to damage. Also of note is the Master Spellthief feat (Complete Scoundrel?) which helps to boost your caster level. Picking up some Ambush feats (Complete Scoundrel) wil lgive you something to do with your sneak attack (other than damage) when facing non-spellcasting enemies.

[gorfnab]

I recommend reading through the Spellthief Handbook (http://www.giantitp.com/forums/showthread.php?t=44299) and the Sneak Attacking Spellcasters Handbook (http://brilliantgameologists.com/boards/index.php?topic=1240.0). Unseen Seer can net you more sneak attack than what is shown on the class table if you choose the spell Hunters Eye from Players Handbook II as your Advanced Learning spell.

[Vknight]

A the silent plotting of a creature know only a power gamer.

i would say do whats the most fun for you

[JaronK]

You absolutely need the Master Spellthief feat if you're going to multiclass or PrC out of Spellthief. Also, note that the maximum level of spells you can hold is based on your spellthief level only, even if you have that feat, so you'll want to have enough levels in the class to hold the highest level spells you plan to face.

JaronK

[Felger]

That sneak attacking spellcaster guide was incredibly helpful, thank you!