Summoner Build?

[Gwazi Magnum]

Basically I'm looking for advice on a build that works well with Leader Ship.

Spellcasting Stat doesn't matter because I plan to swap it to Charisma with a 3rd Party Feat (Unless if I can change Leadership to work with the spellcasting score somehow).

Currently I'm debating between the Classes of Druid and Wizard.

Though I don't necessarily wanted to be pinned down to summoning just zombies or animals, etc. I want to be a fairly open/flexible summoner.

Also any class that can also gain acess to damage spells I can alter with a non-lethal metamagic feat and spells that focus on manipulation or mind control gain bonus points, because this conjurior is meant to make a living in the slave business.

+On the side: Good ways to contain slaves with the class (ex: Enchanting a wagon with spells) would also be appreciated.

[Biffoniacus_Furiou]

I'd go with a Druid, since you can get Greenbound Summoning, Ashbound, and a Ring of the Beast for the strongest summons of any class. Greenbound creatures of any level can use Wall of Thorns to trap targets, since there's no minimum caster level for spell-like abilities (http://www.d20srd.org/srd/specialAbilities.htm#spellLikeAbilities). You also get an extremely efficient damage spell in (Lesser Rod of) Extended Creeping Cold, plus plenty of other damage spells and crowd controls. Additionally, you can get a Fleshraker dinosaur whose poison can disable opponents or at least keep them down until you capture them. With Craft: Poisonmaking from Complete Adventurer you can make your own poisons from summoned vermin considering you get venom immunity at 9th level.

I'd only use Wizard if you can't get Greenbound Summoning or Ashbound, or maybe multiclass into it with Arcane Heirophant if you can get Rapid Summoning (http://www.d20srd.org/srd/variant/classes/specialistWizardVariants.htm#conjurerVariants) and apply it to Summon Nature's Ally spells. Something like Druid 3/ Wizard 1/ Mystic Theurge 4/ Arcane Heirophant 10/ Mystic Theurge 2 with Sanctum Spell or similar for early qualification and retrain or psychic reformation it later.

[Tvtyrant]

I would Wizard into Malconvoker myself, especially if you are swapping Int for Charisma. Add a ring of Might Summons for more HP than gotmilk and a tremendous amount of free spells your summons can cast for you.

[Werephilosopher]

Ditto on the Malconvoker idea. I don't know if by "contain slaves" you mean "slaves that I summon" but Malconvoker is essentially that- a good guy enslaving evil beings to serve him/her. It also has more of a summoner-feel, at least in my opinion, than the druid.

If you do go druid, Biffo's right- Greenbound and Ashbound are prime feats for you.

[Mountain]

Cleric/Malconvoker. You already have use for CHA, and then twin spell+DMM twin+malconvoker means 4x the summoned creatures. You just won D&D. The spell Surge of Fortune can pretty much guarantee any Planar Binding will work.