Improving a Homunculus

[Mr. Zolrane]

So I'm playing a NE drow wizard in an upcoming campaign. As part of my character's background I'm going to have a homunculus (http://www.d20srd.org/srd/monsters/homunculus.htm) (fluffed to physically resemble a Tiny drow girl with wings) with me who my character considers his daughter, and the DM has stated that will probably allow me to spend additional GP after the fact to improve her hit die (as opposed to the core rules, which imply that additional hit die must be added at creation).

My question to the good folk of the Playground is this: What can I do to make her better beyond the basic hit die advancement? Are there any spells or items that would increase her survivability? In general, she won't participate in open combat, but in the even that she runs afoul of some horrible creature, what can I do to improve her chances of not getting killed?

[HalfDragonCube]

In Complete Arcane there is a Prc called Blood magus that gives boosts to your homunculus.

It gives some other nice abilities, but doesn't give full casting, so it really depends on how much you want to put into your homunculus.

Also has some kind of strange entry requirement.

[Dusk Eclipse]

There is a RAW way of doing this, in Magic of Eberron there is a feat called improved humunculus, which says what kind of benefits you can add to your humunculus and how much they cost.