Helping build a Diviner wizard

[TheTwitchyRat]

I am building a caster for the first time I am Only allowed to use spells and feats from SRD (http://www.d20srd.org/index.htm) and 3.5 players handbook. I intend to use this variant

Sorcerer/Wizard
A sorcerer or wizard might desire a more durable companion to accompany him on excursions into the wilderness.

Gain
Animal companion (as druid; treat sorcerer or wizard as a druid of half his class level).

Lose
Familiar.

as it is a short campaign where my back story is that I am a personal hand to the king and my services including being able to find anything, living or not. Any help would be appreciated.

[BowStreetRunner]

What level are you starting? How many levels do you expect this campaign to take you? Some of the suggestions I could offer won't come in until after you reach a certain level. Since you already indicated it will be a short campaign, I wouldn't want to offer any suggestions that aren't going to come up within the levels at which you will be playing.

Are only your spells and feats limited to the SRD, or also choices of race, prestige classes, and so on? There are choices that become much more achievable if you can reach outside the SRD even for just a dip in a prestige class somewhere else.

I will be happy to offer what advice I can, but need a bit more information to get started.